A Guide to Creating a Healthy Home
This post will go through the techniques used to help promote offgassing of the VOCs in a new car.
That “new car smell” is made up of VOCs and we can speed up their release or mitigate them with a number of hacks.
Not all toxins in new vehicles are gasses (VOCs) however. We will also look at avoiding, cleaning and sealing nonvolatile toxins like metals and flame retardants.
[Read more…] about How to Offgas that New Car Smell
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Corbett and Grace Lunsford’s tiny house on wheels (THOW), called the Tinylab, was made as an educational house to teach folks about home performance.
In this article, I’m going to outline the areas of this tiny house’s home performance that are relevant to mold prevention.
These mold preventative aspects of the house are:
I also outline some other facets of the house that make it a healthy home. These are:
I haven’t seen many tiny homes on wheels built really well. This is only the second one after Terran’s house that I have featured as a mold preventative build.
In Corbett’s High Performance house, air sealing is incredibly important. Air sealing is how you prevent air from entering the wall and other cavities. This is important because air carries vapor, and it’s usually at a different temperature.
Air leakage brings with it vapor that can condense on hidden surfaces.
This build used materials that are made for Passive House design. Passive House is a design process that includes a major focus on controlling for moisture and condensation within the walls, ceiling, and foundation.
Solitex Mento membrane and tapes were used, just like in this detailed example.
Solitex Mento is a breathable house wrap/WRB that comes with a line of high-quality tapes for sealing around all seams and openings.
Most houses should have a breathable exterior water-resistant barrier over the sheathing, with a vented rainscreen system. A rainscreen is battens that create a gap behind the siding. This lets moisture escape and dry out.
These products are good at air sealing and they are also lower VOC than liquid applied barriers. Many high-quality builders are now using liquid applied barriers in many areas of the house, and that might not work for all chemically sensitive folks.
Inside, the Intello brand smart vapor retarder was used to prevent moisture from entering the cavity in the winter and let it breathe more in the summer, preventing condensation within the wall cavity.
We want to get away from using vapor barriers that trap moisture. Instead, these two permeable membranes, one on the outside of the wall and one on the inside, control air flow, and slow vapor flow but don’t stop it completely.
With Rockwool R 15 in walls and ceiling, the Tinylab house can be moved around the US to multiple climates. You always want to design the house with one climate in mind to optimize all the systems (and the whole house as one system).
This house was built for Atlanta. As they moved the country they had the most difficulty with humidity and condensation in very humid and very cold climates. They attempted to follow the weather to reduce this challenge before returning to Atlanta.
Rockwool is easier to pressure fit into cavities compared to cotton batt. They tried the recycled blue jean insulation at first, but it was sagging in the ceiling, and leaving a little bit of air gap in the wall cavities. You can see that here.
Rockwool holds itself in well with a friction fit in both the ceiling and the walls, without sagging and leaving air gaps. The tighter it is to the framing the better.
If your insulation is not tight to the framing air leakage can lead to moist air moving through the wall and condensating. A lot more moisture moves into the wall with air leakage than with diffusion. Diffusion itself moves very little moisture, not enough to cause problems in a well-designed wall. Matt Risinger explains that in this video.
You need to take your time to cut and fit the insulation as perfectly as possible so that you don’t have air leakage.
They didn’t use spray foam, even though folks like the idea of insulation that in theory is an air sealant and a high R-value insulation product in one.
In reality, spray foam often pulls away from the walls, in which case you lose the air seal. And in a tiny house on wheels that is moved around, it’s going to crack and come apart from the studs almost for sure. Bad idea.
Here is the interior air barrier and air sealing:
There was a big focus on 0 and low-VOC materials throughout the whole build which I appreciate seeing, even though the Lunsford family is not chemically sensitive.
Purebond plywood which is made with a “soy glue” (probably a polyurethane glue) was used for the interior walls and cabinets as well as the interior door.
If you are sensitive you should test this out for yourself. I prefer plywood made with phenol-formaldehyde which has a defined short period of offgassing before it cures, compared to an unknown glue and VOC that we know less about.
For the walls here I would have preferred just a solid tongue and groove wood. With plywood only used for cabinets.
The floor is APC Cork, which looks awesome and is great for sound dampening. For most moderately to severe chemically sensitive folks, cork flooring is too high in polyurethane glue (and VOCs).
There are many similar floors you could put down in a tiny house that are extremely low (lower than this) in offgassing. I list them here in my flooring post.
Both Rockwool and EPS (polystyrene) foam insulation are used in the house. Both healthy choices. Rockwool is my go-to insulation to consider before moving on to more unusual options.
My insulation post goes more in-depth into insulation choices and why rigid foam is still a good choice for most sensitive folks.
Rigid foams are frequently used as exterior insulation (outside of the framing) as part of the system design to prevent thermal bridging and to help prevent condensation.
This video has some good information on the insulation:
When designing and building a mold preventative house, the devil is always in the details. Flashing is an area that is more often than not done wrong on new builds (along with the air sealing layers like the house wrap).
I liked this detailed video below on how to properly install a new window to prevent future moisture issues.
Maybe this looks simple and like anyone who can follow instructions can do it, yet almost every builder makes mistakes here.
It’s rare that I see a build in progress with the house wrap/WRB and all flashing done right. You should supervise this part of any build.
When windows and other openings in the exterior are not detailed right, water that gets behind the siding finds its way to the plywood or OSB sheathing. Enough moisture will cause water damage and mold here. As damage continues it will get into the framing and wall.
In regular builds, other openings in the wall for vents or wiring are often left without any sealing (flashing)! Big problem for water and air getting in.
Water is expected to sometimes get behind the siding – that’s not a fatal situation. It’s supposed to be able to drain, dry to the top and bottom, and stay out of the walls.
The windows are Pella brand wood windows with aluminum cladding on the exterior. The caulking recommended for this combination of materials is DAP 3.0 Window, Door, Trim & Siding High Performance Sealant.
Here are the WRB instructions from 475 if you prefer diagrams to video. All the brands come with detailed instructions, there is no excuse for a builder to not know how to do this.
The object in the Tinylab is to have active balanced and controlled ventilation.
It’s easy in a tiny house to create negative pressure with a high CFM (CFM is the amount of air it’s moving) bath fan or range hood. This pulls way too much air out for such a small space. This can happen in any well-built air-sealed house, but it’s exaggerated in a small space.
The problem with that is that you start to pull in air back through any gap that the air can find a path through. And back through places you don’t want to pull through – like exhaust vents or even the composting toilet in this case! You might also be pulling in moist outside air.
You aren’t getting healthy make-up air this way (which is the air that’s coming in to make up for that exhausted air).
Without enough air exchange (air coming in and going out) in a small space, you can also raise your carbon dioxide.
Having air exchange (meaning you replace the indoor air with fresh outside air in a controlled way) is the best way to reduce carbon dioxide, VOCs and other pollutants, like those produced by a gas stove.
This house has a number of high tech ways to manage the air quality and replace the air.
A Broan HRV (later switched out to an ERV) exchanges indoor and outdoor air in a balanced manner. The ERV is working better for them in their climate because it buffers both humidity and temperature.
You need to look at the house as a system and your climate to determine which one you need.
The negative air (exhaust) side of the ERV is venting out of the bathroom, and the positive air (incoming air) is coming in over and under the loft.
The fresh air comes into the loft area with a damper to control whether it goes down to the sleeping area below.
This video explains what an ERV and HRV do and what the difference is.
The composting toilet and kitty litter box area has a 3 CFM exhaust vent to keep that air moving out (a very small fan, just enough to keep it moving out).
The gas stove has an exhaust fan venting out over it, to pull out moisture, carbon monoxide and other pollutants and particulates from cooking. When this fan kicks on, it opens up a damper that brings in fresh air right under the stove. This keeps air circulating and moving out right where you want it to.
You can see it in action here:
The house has a number of cool monitors that help you know that everything is functioning as it should be.
Defender brand low-level Carbon Monoxide monitors detect low levels of carbon monoxide. This is important if you are running appliances on fuel. Your carbon monoxide level should be 0 in a healthy home.
Elderly, children and those with compromised health are more affected by low levels of carbon monoxide. The cheap monitors are only going to show you when the level is already too high.
Corbett has a radon monitor from Trutech tools, which is useful in a regular house. Though here it is used for teaching purposes. If you are not on a foundation you don’t need a radon monitor. (Though if you have a granite countertop this might be interesting to see!)
Corbett is aiming for 0 radon in all his houses.
The Foobot monitor tests for carbon dioxide (what you breathe out, this will show you if you have enough fresh air), VOCs, particulates, temperature, and humidity.
Retrotec manometer measures the pressure inside, making sure it’s where you want it to be. In the Tinylab they are making sure it’s more or less equalized.
It also monitors the pressure of the incoming air through the ERV. Just an extra data point to show Corbett that everything is functioning, and for educational purposes. For most people, this extra step would not be needed.
Though it would be interesting to see the pressure in the house as a whole. Just seeing that would tell you if something is wrong with one of your fans or exhausts.
Two Dwyer temperature gauges measure the temperature of the incoming air through the ERV, and the air inside the wall on the backside of the insulation. These show how well the house is managing the temperature.
The temperature gauge on the inside of the sheathing can help you to calculate if there is a risk of condensation on the sheathing or exterior vapor barrier (if you have an exterior vapor barrier). Especially if that is coupled with air leakage (which you can use an infrared camera to check for).
A third gauge wraps around a plumbing pipe under the stove to see if there is a chance that pipe will freeze. Smart!
The greywater tank is on the exterior and is portable and on wheels. I like this idea as you don’t have and scum build-up inside hidden tanks. And not having a blackwater tank definitely cuts down on the kinds of bacteria and mold you might be fermenting in your tanks. (They use a composting Air Head toilet instead).
The freshwater tank, stored inside under the sink, won’t freeze. It uses chlorine to keep it bacteria and fungi-free, it’s not for drinking unless you want to filter the chlorine out.
In the last section, you can see the major leak they had with this tank and how they put more precautions in place after that.
They have three solar panels that are portable, on a long cord and are set up on the ground. They can be moved around to maximize sun exposure. It’s not a great idea to put panels on the roof; more holes = more chance of leaks there.
You can also plug the house in; the whole house runs on one extension cord that runs off a regular house outlet (15 amps). That is an impressive (low) amount of power usage. It gives you the ability to be super flexible with where you live. Either going off of solar and propane, or one plug into any house.
The stove and hot water heater run on propane, which cuts down on electrical usage.
The Mitsubishi mini-split only needs to produce 5000 BTU of heat, 4000 BTU of cooling to keep this house warm and cool enough for their climate. It runs off only 200-300 watts.
This is something you need to calculate in at the design stage. You don’t want an oversized or undersized system.
Mini Split heat pumps are ductless systems, they do not bring air in or out of the house.
This does a little bit of dehumidifying, and in some conditions, the ERV helps too. But they also found they had to add this desiccant dehumidifier.
This video shows the mechanical systems and is a good overall tour:
The base of the house was designed to use the trailer cavity as an insulation cavity. EPS foam with foil backing was placed in between the metal trailer joists.
Underneath the whole trailer, there is a metal barrier to prevent water from splashing up. There is no thermal break underneath the metal trailer framing. This is a typical design for tiny homes on wheels.
On top of the framing, plywood is placed against the metal. It looks like there might be a slight gap between the EPS and the wood.
I wouldn’t recommend this design of the floor system in terms of preventing condensation and mold.
In fact, the flooring system is where you should put the most thought and planning. Bring in an architect like Cheryl Ceicko, or Passive House designer like Mike Maines.
It’s easy and common to have condensation in the flooring of a tiny house on wheels. The metal trailers make this difficult. There is a lot of thermal bridging. You need to decide between thermally breaking this underneath with foam or building up a breathable system on top.
Those who have designed with mold prevention as the main goal have all built up on top of the trailer. This post shows a detailed example.
EPS is also used around the metal wheel wells, a place that is prone to condensation.
The roof has plywood decking with foam exterior insulation on top (1 inch EPS), then Solitex Mento, then a rainscreen, then 26 gauge metal roofing.
The walls are regular 2 x 4 framing with Rockwool, plywood sheathing, a rainscreen, and is breathable to both sides with the Solitex and Intello products.
Make sure your rainscreen is vented, it’s a tricky detail in tiny houses on wheels.
The Freshwater bladder did leak and it was quite the flood. After that, the Lunsfords put some precautionary measures in place.
Anyone preventing mold would want to do this from the start, making sure a leak-prone area is a waterproof protected area and you have these leak alarms.
The foam mattress was put right on the floor. Always a no-no! This causes mold underneath. They changed over to an air mattress which does not let moisture transfer through it.
They also had condensation on the wall in the backside (at the back of the drawers that were full of clothes and things) on the really cold days. That’s a place to keep an eye on. You may even want to design your storage a little differently in a cold climate.
Corbett doesn’t have unrealistic expectations on how long a tiny house will last. He says no more than 30 years.
They put a lot of miles on the house but it was designed with an engineer to make sure that it would hold up to those forces. In that sense, it was designed well for the motion.
Building a tiny house when you have sensitivities is in a way a trickier endeavor. You are in a much smaller air space with all the items that offgas that you can’t avoid – appliances, flooring, caulking, glues, windows, doors.
You are also in a much smaller space with EMFs and you cannot get away from that.
In the end, I still like tiny houses for those with mold and chemical sensitivities, but only if you know full well what you are going into and have taken the time to design a detailed mold preventative build.
There’s a lot of work involved here – you are designing a full system. Just about as complicated as a regular-sized house.
The only part that is easier due to the size is that you have an easier time supervising the build. The HVAC is also less complicated.
I am currently taking Corbett’s course in Home Performance to become certified with the BPI as a Building Analyst. Corbett consults on home performance, and you can contact him here.
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This article covers the sources of mold growth in vehicles – AC system, high humidity storage, spills, leaks, and design malfunctions – and how to prevent them.
I go into detail on the four methods used to clean the HVAC system out, as well as methods to clean mold and cross-contamination in the vehicle as a whole.
The AC is usually the most difficult area in the vehicle to manage microbial growth. While there are certain makes and models of vehicles where this is more of an issue, to some degree it’s a problem in all vehicles due to the inherent design of the AC system.
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The fungi and bacteria grow mostly in the evaporator core and immediate surrounds, due to humidity and moisture that forms when AC is in use. Mold can form in the ductwork as well.
To help reduce mold formation in the AC system, run the fan for the last 10 min after using the AC. (Defrost is also AC, so you need to run the fan for 10 minutes after defrost as well). This helps the evaporator dry out.
Using recirculate can worsen the problem in some situations. Bringing in fresh air (if the outdoor air has drier absolute humidity) as opposed to using recirculate can help the evaporator to dry out.
Another thing you can do is to avoid parking in areas where a lot of debris can enter the air intake.
Similarly, when driving through very dusty areas, you are bringing in dust and spores through the air intake. You may want to turn off the HVAC system completely in those conditions.
Maintenence on the vehicle should include changing the cabin air filter as needed (when it’s dirty).
I would include one of the four HVAC cleaning methods below as a preventative (before you start smelling or reacting to mold) if you do use the AC system regularly.
Many folks who are extremely sensitive to mold do not use the AC system in their vehicle at all. If you refrain from using this right from the start with a new car, you will avoid most of the problems here.
If you want to avoid AC use altogether, using just the heating system should be fine. But, keep in mind many new vehicle models have automatic climate control which will use both heating and cooling under many different conditions (not just when defrosting). If you want to turn off the AC, look for a vehicle where this can be done – new cars have a way to disconnect the AC compressor. Ask a mechanic how to do this.
If you have already used the vehicle’s AC or you bought a used vehicle that has some funk in the HVAC system, then even the heating setting will circulate the fungi and bacteria throughout the vehicle.
Buying a vehicle with heated seats is a good idea in case you become sensitized to the vented HVAC and need to turn it off for a while (and try and clean it). Some very sensitive folks have had to turn it off permanently if they have not had success with the cleaning methods.
One other hack is that you can externally mount the HVAC system to get easy access to the evaporator. This is a very unusual hack. You can find photos of it in the group Mold Avoiders on the Road.
Some of these built-in systems blow unrefrigerated air through the cushions. And some use refrigerated air that is tied into the main AC systems. The unrefrigerated air system may be safe in terms of mold prevention.
You can also add your own cooling and heating seats to avoid the use of your car’s HVAC system.
Cooling seats that you add yourself work simply by adding a fan that blows unconditioned air which helps to cool you down.
This one (pictured) that uses fans is affordable.
The heated seats use coils, just like a heated blanket or heated jacket. Some models like the Naipo do both.
Then there are gel seats, I like the idea of the ones you put in the freezer first, then you bring it out to the car with you. This is a kids version. If you know an adult version let me know, I think it’s a good idea. You will want to dry those off though, when they come out of the freezer they are probably going to condensate.
When I used to have severe heat intolerance, I used cooling vests on my body – both active and passive vests work.
The active vests provide more cooling but are more expensive.
They were life-saving for me until I healed from heat intolerance.
There are a few ways your vehicle can become moldy inside on the seats and upholstery. Sometimes just leaving a car to sit in a very humid place for long periods of time can cause mold to start growing on the seats.
More common though, is a spill or window left open that wasn’t dealt with fast enough.
Other sources of water damage are less common:
Prevention here is key. Once mold is actively growing and has made it through to the foam in the seats, it’s a huge problem that is hard to fix.
When storing your vehicle for long periods of time in a constantly humid climate, it’s best to leave it in a sunny spot and leave it with a dehumidifier. Climate controlled indoor storage is of course ideal.
Though generally, a vehicle should be able to withstand a good amount of humidity while being stored, really high humidity for long periods has been a problem for me. I left a truck in 70-95% humidity for a couple of months and came back to mold growth. No known water intrusion.
Many others in the Pacific North West and similar climates have left vehicles sitting to come back to visible mold growing (and not from leaks).
Both active (battery-powered), and passive dehumidifiers will help. You can also monitor the outdoor humidity.
I would check on the vehicle (or have someone check on it), both to empty the dehumidifiers and possibly to dry the vehicle out actively with heat and airing every few days if necessary.
When you spill something or leave the window open, just do everything you can to dry it out within a day, which includes the above: usually sun and air, or heat and air. Add dehumidification only if it’s going too slowly.
DISCLAIMER: Some of the cleaning methods discussed in this article, that include ozone, chlorine dioxide, hydrogen peroxide, and quaternary ammonia, require knowledge of safety precautions for handling the materials, and executing these methods. Please take full responsibility for your health and wellbeing and make sure you understand the risks, precautions, and procedures – not all of which are explained here in full (please research them before proceeding or consult with an expert). Full disclaimer here.
If you do have some light surface mold in the car or cross-contamination, I would start with a deep clean.
If you had a big spill that didn’t dry out, or you suspect someone else did in your vehicle, you might want to open the seat covers to check on the foam. Some have zippers. If they don’t you would have to cut them open to check.
Mold in the foam cannot be properly remediated other than with replacement.
You can remove light surface mold or cross-contamination by steam cleaning or shampooing the seats.
Make sure it is dried out quickly after that. Car detailing shops can do this. Just make sure you know which products they are using, as some might not be acceptable, toxin-wise.
A mechanic I talked to near Vancouver BC, does a shampoo of the seats with high temp extraction, then an enzyme spray on the seats instead of ozone to reduce odors. I use similar enzymes to break down odors.
If it’s not so bad as to warrant a steam clean or extractor shampoo, use a HEPA vacuum, which you can do your self. Vacuum the seats and carpet, and upholstery.
For a vehicle, you want a rather flexible hose. I would use the Shop-Vac. I’ve used this one before with the HEPA filter and HEPA filter bags.
You can then wipe down all surfaces with quats or the cleaning product of your choice. A proper HEPA sandwich would involve another round of vacuuming.
Having your car or truck professionally detailed can help, as they do a very thorough clean, though I haven’t seen them do HEPA vacuuming.
If those methods don’t cut it, and you are still sensing mold in the vehicle, you will want to use the methods below.
Many people do use ozone and it does work, but it leaves behind oxidation, which smells quite terrible.
Depending on how long you ozonated it for, it can take a while to die down.
I don’t agree that you will damage the wiring easily, you would have to use extremely high levels for a very long time to do damage like that. Many mold avoiders have ozonated vehicles at very high concentrations for 24 hours, many times. I have done a couple 24-hour treatments on my truck.
Car dealerships use this all the time as well (but normally in much shorter treatments, like 1 hour). Many people only do 2-hour treatments for mold, which should not cause damage to the plastics, and would only cause minimal oxidation odor after.
There is more info below on pumping ozone through the HVAC. If you don’t need to pump it through the HVAC, just see my general post on ozone and run it inside the vehicle. I use the little Airthereal.
Please read through the precautions thoroughly, since ozone is a dangerous gas that can be deadly.
Another oxidization method, though it is a weaker oxidizer than ozone, is to use chlorine dioxide gas. That method is explained below, in its own section.
If you have another decon method that has worked well for you in decontaminating your house from mold, it’s likely you can use that here – like thieves oil fogging, Concrobium fogging, or using quats.
Silver Hydrogen Peroxide though, is likely too much oxidation for most vehicles, though it can be used in the empty part of metal cargo vans.
Chlorine Dioxide, like ozone is an oxidizer. Like ozone, there is evidence that it breaks down mold and mycotoxins.
Although it’s weaker than ozone, you should take the same safety precautions outlined here. It is dangerous to breathe in and it’s explosive in certain concentrations.
You may not need to be so far away from it like with high doses of ozone, which is an upside. It’s also cheaper and easier.
Keep it simple and buy the ready-made tablets or packets on Amazon. They are inexpensive and work just as well as mixing it yourself. NosGuard is one brand, Reset is another one.
Read the safety instructions carefully on the product and make sure you understand them. Never use a chlorine dioxide product in occupied spaces.
If you want to make it yourself, please take full responsibility for your safety and wellbeing. Here are the instructions:
How to make chlorine dioxide gas treatment for the home or car: 6.5 oz (roughly 3/4 cup) Oxine plus 3-4 tsp citric acid in glass or heavy plastic container, one for each room. Leave it for 3 hours for a shock treatment or 24 hours for a deep treatment.
You can make a smaller batch for smaller spaces with the same ratio. It takes about a minute for the reaction to take place, the liquid will turn yellow, and for about 3 hours it will release chlorine dioxide as a gas. Take similar precautions as with ozone for airing it out and re-entering.
Skill Level – Easy. Results – Can work, depending on which methods they use.
There are a number of different cleaning methods used by automotive repair shops to clean out the AC system. Some use ozone and even run it through the HVAC in the same way as described in the next section on ozone.
There are also treatments that are similar to #4 on this list, introducing a product into the system to clean the evaporator.
One mechanic explains: “one is a mist treatment, using a product which foams up. You drill a hole in the case and then introduce the mist to the evaporator core and let it sit, give it time to work, and then flush it out.” (source).
Some of these might have fragrance of other toxic additives but others would be acceptable for many folks who are sensitive.
Skill Level – Intermediate. Results – works on most mold and bacteria.
This is a technique used by some car detailers and dealerships and mold sensitive folks.
The simplest way to do it is to run an ozone machine in the car while the vehicle is running so that the ozone is pulled in through the air intake. Most people would run this through for a couple of hours. Depending on the amount of ozone and the time you run it for, you may need a window open to provide oxygen.
If you are running the machine in the car I would use a small machine like the ones on Amazon for under 100$.
Instead of running the vehicle, you could alternatively, hook up the battery to a battery charger to run through the HVAC settings that way.
For any serious contamination or if you want to blast this more directly through the HVAC, mold avoiders tend to use an external ozone machine that pumps in the gas, giving the machine full access to oxygen outside. Bioblaster is the most popular one.
If you are in the Facebook group Mold Avoiders, you will be able to see an example of a Bioblaster hooked up right to the air intake here.
That machine is overkill for me. But others may need this. I would have no problem running the smaller ones on Amazon that I have used many times and pumping those through the HVAC system with tubing from the outside.
To get it through all the different parts of the HVAC system, the ozone needs to run through it on all settings (heat, AC, recirculate). Run it through each setting for at least 20 min. The next section explains more about how to access the air intake.
This is tricky because of how far away you need to be from the ozone. Let it air out each time before coming close enough to the vehicle to change the settings. Again, ozone precautions are here.
Skill Level – Beginner to Intermediate. Results – May or may not work.
In this method, hydrogen peroxide or quats are sprayed through the air intake.
Some very mold sensitive folks have had success with 10% hydrogen peroxide sprayed into the air intake with these video instructions (not with toxic products like scented Lysol). Seeing the process in a video really helps to make sense of it.
Spray the hydrogen peroxide through each setting for 3 min. You can use this mister.
You will be using 29, 30 or 35% peroxide (depending on what you can source) and diluting it down to 10% (here is the dilution table). Please research and take full responsibility for handling and spraying this concentration of hydrogen peroxide.
Some people found this worked better with quats (a type of ammonia). This ACDelco product was recommended.
Skill Level – Very Advanced. Results – Likely to work if you do it right.
Greg Muske from Biotoxin Journey has a detailed and more complex method of accessing the entire HVAC system and runnings quats (quaternary ammonium) through it.
You need some mechanical expertize for this method as it does involve drilling into specific parts of the system, which differ depending on your make and model.
You need someone who can understand the heater core diagram for your car, which you can look up online. You’re going to locate the evaporator core. Then drench the two cores by running about one gallon of quat solution into 3 access holes. Followed by a water rinse.
Greg also misted quats through the ductwork via the vents and the opening for the cabin filter directly above the blower (after removing the filter), and air inlet holes located under the hood next to the firewall. Unlike when cleaning the cores, this was not rinsed out. It was dried out by running the heater and fan on high.
Greg then cleaned out the rest of the car by using a steam cleaner on the carpet with Thieves Oil Cleaner. (You can use the cleaner of your choice). All other surfaces in the vehicle were wiped down with quats.
Full instructions and a video can be found here: Clean Driving Machine. This section was printed with permission from Greg Muske.
Corinne Segura is a Building Biologist with 6 years of experience helping people create healthy homes.
This post was written with input from an engineer, a mechanic, and a car detailer.
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Highly skilled builders are rare. They tend to focus on upscale houses because that extra work and time they spend to build something right does translate to more expensive homes.
Most tiny house companies I have seen were started by contractors who don’t have much experience, they certainly don’t have the expertise in building science (which is mold prevention), and high craftsmanship.
Most small companies I have looked at started with someone who had not even managed a whole house build before! That was the case with my builder.
Even if a company is well established, it’s rare that an architect or other building science expert is recruited as a designer and consultant on a tiny house build. It is necessary to have that building science expertise to building anything that will hold up to mold, no matter the size.
My resource page contains links to architects, builders, and building science experts who I think are good.
I certainly wished I had chosen an experienced builder who really cared about details, and hired an architect to design and manage the project.
Building codes are not perfect, they are only the bare minimum requirements and even though they are just the absolute bare minimum of what needs to be done on a house, they are not usually followed.
To build a truly mold-resistant (regular) building you have to hit many of those codes right on and in many other areas go above and beyond those codes if you want the house to hold up to moisture and mold.
Tiny houses don’t even meet those codes on some of the most basic building standards. If you are having trouble finding a regular house that does not have mold, I don’t have good news, tiny houses are built even more poorly.
For some areas of the build, RVIA certification could help ensure things are done better. But some RVIA codes are not mold preventative (like the requirement a vapor barrier), that could make things even worse!
Look at RVIA codes and see if that will work with your moisture management system. You may have to forgo that certification. There may be important guidelines to follow there for general quality (plumbing, electrical, fire safety), but not necessarily for mold prevention.
You can build a mold preventative build (like this one) and also meet the International Residential Code (IRC) (which would be a good idea).
All Tiny Homes on Wheels are built on a metal trailer – that’s a tricky interface for condensation in most climates. Building the house by using that trailer as a floor cavity is a bad idea.
The house should be built up on top of the trailer, and even then there are many very detailed decisions and details to consider and execute. See this post on a Mold Preventative Tiny House for details on the trailer base.
Many THOWs are also made with metal framing. That is really tricky too! Now you have a whole house with thermal bridging and the possibility of condensation in the wall. Even if you go with all foam for insulation, this has to be well thought out and designed well.
I have seen trailers with a metal frame and then an organic insulation! No!
The wheel wells, another metal area, are also particularly difficult to insulate and are usually done wrong. The wheel wells in my tiny house went moldy within the first 3 years. They need to be thought out and detailed right.
Hire a building science expert to design your building envelope.
Tiny homes are often moved throughout many different climates in the US and Canada. Which climate was it designed and built for?
Even if some thought was given to design the building envelope and HVAC for that climate, will it now be moved to many different climate zones? How will the house perform in those?
If the house is made for multiple climates that has to be factored into the design of the entire envelope and moisture management system as well as the HVAC right from the start.
WUFI is one program that you can use to model the moisture in the house and see how it will perform in various climates.
Taking a house and then jostling in on the highway does not lead to something very durable. All those little details that need to add up to have things perfectly sealed and flashed do not benefit from a lot of movement.
You can easily lose the integrity of your sealing or flashing here, you may even have trouble with your framing or siding. Problems with your framing could lead to problems with your doors and windows and more…
Many tiny houses are very expensive and only come with a one year warranty! What!
What other 60K item would you buy that only has a one year warranty? Builders can get away with a lot because major mold problems will take longer to show up than one year.
My house had a few problems in the first year, but there were other major problems that took more than a year to show up. Mold above the shower in the ceiling, mold on the framing, an insulation system in the floor that was not done right – I fixed these myself on my own dime.
Ben Garrett (Tiny Healthy Homes) who built my house only paid for things that went wrong in the first year. He then changed the name of his business (and so I could not sue him). That’s another reason these small companies are very risky. I lost 100k as a result of the building defects in that house.
Though I did learn a lot about building science when I took it apart! And this did lead me to become certified as Building Biologist to help others build low offgassing, mold-safe houses.
The most helpful course in mold prevention is Cheryl Ceicko’s Building a Healthy Home.
Siding is frequently done wrong on tiny houses. Mold preventative siding almost always has a rainscreen with very few exceptions.
Regular wood-framed houses almost always require a vented rainscreen siding system to prevent water damage and mold. This is rarely done on a tiny house.
Most houses I have seen have siding right up against the sheathing. Sometimes it’s permeable siding, meaning solar vapor drive can drive moisture in, but even if it’s not, it prevents drying from the inside out. And you are losing your layer of protection from water entering behind the siding.
A rainscreen helps water that will get behind your siding drain out.
I highly recommend Cheryl Ciecko’s course on building a mold preventative house which is now evergreen, you can start the course at any time.
To hear about future course you can sign up for my email list:
Regular sized houses have a fairly complex roof system that often has venting. An unvented roof (like tiny house roofs) would have to be done really carefully.
In a small space, your roof cavity can start to mold fast. Mine did over the shower as the builder had no interior vapor barrier and the breathable roof sheathing membrane was enough to trap moisture there.
Many tiny houses also have roofs that are flat or don’t have the right material for the slope.
Here is an example of a highly detailed mold preventative roof.
The devil and mold prevention are in the details. Window flashing, house wrap installation, house wrap taping, metal head flashing, the detail below the rainscreen, flashing on any permeations going through the wall, details around the door- all of these are super crucial.
It’s especially important to get right due to the lack of overhangs over windows and doors on most tiny houses. This means everything has to be done perfectly. The overhang on a regular house is insurance against too much rain hitting these vulnerable areas.
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This post is about two highly insulated shelters I made with rigid foam, raised off the ground and covered in a tarp.
These shelters are super simple, super tolerable for the chemically sensitive and are ideal for mold avoidance in cold weather (or even in hot weather).
This has the same insulative value that a house would have. I was very warm inside in Canadian winters with one space heater. This shelter can work in any climate, though it will not survive a hurricane! It was highly tolerable for MCS and a good set up for mold avoidance.
These shelters were an incredibly important step in me healing enough to live inside. The shelter was the last step in mold avoidance before I moved back inside. I moved back into regular housing for the first time in 8 years, and I continue to recover.
This is something I wish I had known about much earlier on, as tent living and custom trailers/vans are difficult to make and to live in, especially in cold weather. It’s hard to keep a steady temperature, it’s difficult to insulate trailers and vans, and it’s hard to keep them from going moldy. This shelter solved all those problems.
A wood frame like mine (pictured) is needed to protect the shelter from high winds and snow. My frame was very robust, survived a massive wind storm and big snowfall. If you don’t require snow and wind protection, simply tie up a tarp over the raised up foam shelter and skip the frame altogether.
The shelter is made of a plywood platform and a wood frame, though you could use metal or another material. We used some pressure treated wood for the framing and some non-treated wood.
Most of the points touching the ground are stumps, for added protection from rotting out (you can see that in the vide
The interior is an XPS foam box. The box was made to fit the plywood, it was 4 x 6 feet but you can make this any size you choose. The height we decided on was 6 ft.
You can use any thickness of XPS that you want. Though for this to hold itself up without any supports (other than tape) as it’s designed, I would use 2 inches.
What I would do differently next time is paint the foam with ECOs primer and paint and possibly seal with shellac. This will seal in flame retardants and the very minimal off-gassing. Most extremely sensitive people do well with this foam.
I made a model to test out ECOS paint and shellac and it worked really well (both the porch paint and the vinyl siding paint worked). With or without Zinsser Bullseye Shellac.
I would also use clear tape next time because it would look better!
I would buy a tarp that covered the wood but still had air movement underneath.
When you are heating you should seal up as much as you can on the inside with the tape that you tolerate. Green painters tape or Siga tape are the most tolerated types.
When taping the outside in heating season do not cover the seams fully, just enough to hold it together like in the videos.
In cooling season it’s the opposite (if you did put AC in there).
Such a robust frame is not always necessary. You can build the plywood platform, with foam box on top and simply string a tarp over this if you don’t have strong winds or a lot of snow.
A number of details are necessary to control condensation on the inside of the tarp in heating season, as condensation can drip down onto the wood or foam. We used spacers on the sides, a criss-cross on the top, and a piece of plastic suspended above the roof of the foam shelter to stop water from dripping down and wood from getting wet and moldy.
Please contact me for details if you want help setting something like this up.
This shelter worked extremely well though there are things to keep an eye on in the long term. Here are some video tours which will help you to picture how it works, shows the spacers, and other details like windows and power.
The whole thing was completed with some volunteer labor and some paid labor for 1000 CAD. I used two 100 ft extension cords (10 or 12 gauge) to power this heater and my laptop and light. You need one dedicated 10-12 gauge cord if it’s 100 ft, for a 12.5 amp, 1500 watt heater. Plenty of heat for a small space! You can’t have anything else on that circuit in the house it’s running from or inside on that cord).
I used this plugin thermostat to control the temperature and keep it very even (which needed a surprising amount of offgassing). I strung up this bulb (the string needed some offgassing).
I used the Mondo King Thermarest and I covered it in two Husky bags (taped together) to keep it dry. A small fridge was kept outside in my trailer, on a different circuit.
I used this little portable tub to “shower” in outside, and the luggable loo. More pictures of the framing:
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This is an interview with Solona, a fellow Canadian, who I have known in the online world for a few years.
I have followed her journey from severe MCS, to planning effective toxin avoidance, to 85% recovery in just 4 months. She’s still in the journey, but is recovering quickly.
Update! After one year of mold avoidance, Solona has effectively recovered her healthy! She now has a YouTube Channel that is very helpful for those starting out.
Here is a tour of her amazing decommissioned ambulance.
I wanted to interview Solona because she had and overcame the key bottlenecks which are:
We talk about a couple books in this interview – the Beginner’s Guide to Mold Avoidance by Lisa Petrison, and Bryan Rosner’s book Lyme Disease Supercharge (which is actually about Mold Avoidance). I want to add Julie Rehmeyer’s book Through the Shadowlands to this list of helpful books in this journey.
Corinne: This is my first interview. I want to do a healing from MCS, mold illness, healing from CFS series.
I want to talk about the journey from severe MCS, to quite a rapid healing journey.
I want to inspire other people who are starting out, who have high MCS, who want to go further with avoidance in order to get better. Not to just avoid avoid avoid and go in circles.
Is that correct, would you say you had severe MCs, I remember you talking about fragrance residue on packaging.
Solona: Oh definitely.
C: Did you have any other symptoms like fatigue?
S: I was diagnosed with CFS, I think about 20 years ago. I was bedridden for a few years. At my very worst, the scariest symptom I had was paralysis, especially around gasoline. I would lose the use of my limbs and I couldn’t walk or use my arms. And then I would get slurred speech. Those were the scariest symptoms. Then the garden variety ones also.
C: And I remember the forest fires, was that a big turning point? We are talking about the interior of British Columbia, Canada. The fires hit hard, 2 years ago, was it?
S: It was last summer. The big clue that this was mold, was that I relapsed after nearly 10 years of being mostly recovered. After being in Ontario. I went to Ottawa for a job. It’s really bad there and I crashed within about 2 months. I moved back to my home in BC to get well, then the forest fires hit in 2018, and even when they cleared I did not recover.
C: So Ontario was worse
S: Ontario was what made me crash, for sure.
C: One thing I found really interesting ….We were both in the Canadian groups for MCS and other groups. I have seen you over time, though we haven’t talked on the phone, I don’t know you really well.
But one thing I saw that I wanted to talk about is I have seen photos of your house [where you were really sick right before avoidance]. I think at the time you did think you were avoiding mold. Is that because it was better than many other houses? And you were able to sense mold in other houses?
S: It’s because I never knew about extreme mold avoidance. I had a very good sense of smell so I can smell mold. I had no idea about outdoor toxins or molds you don’t smell, molds you don’t see. I was living in mold and I didn’t know it. And that’s why I didn’t recover like I did before. And I can’t really explain why I was OK in that house a few years prior.
But I can say I have recovered symptoms that never went away before, now, with mold avoidance.
C: Houses get worse over time if there are errors. It wasn’t a very new house, what was it from the 70s?
S: 70s yes.
C: I’m also in BC and the houses are not well built.
A lot of other people are in this stage now – you had no visible mold, no water stains on the ceiling, right?
S: No, nothing obvious
C: No smell of mold. Did you have a basement?
S: No
C: basements are often musty, but you couldn’t get under it to see if there were any problems.
S: As I later learned, once I unmasked I didn’t really tolerate the area well for some reason.
C: When you started the more extreme avoidance you moved from one area of BC to another. Not extremely far. Some people do mold avoidance and they feel like they have to go to the southern US or even to the Caribbean.
S: I think it’s about 3 and a half hours [from the moldy house in Slocan Valley] to Kelowna [the first new location for avoidance]. The thing is, I learned through experience there are levels of unmasking. And I think I unmasked and cleared out and healed to a certain degree in Kelowna until I left went to an even clearer place [Idaho] and came back. I cleared out even more and now I don’t think I can tolerate Kelowna.
C: OK, you started in the Slocan Valley where your house was, then when you started mold avoidance you went to Kelowna and improved, and then you went to northern Idaho and improved even more?
S: That’s right. I spent a week in northern Idaho and felt incredible, and did a tonne of healing even in that one week. And then went back to Kelowna and instantly felt sick again and my symptoms got worse the longer I stayed.
C: [Going back in time again] I’m interested in that time, where you got a lot worse, you went to Ontario, probably hit a moldy building, came back and then hit the fires, and everything was really hard. But what do you think lead you to that shift [to mold avoidance]….
S: You did!!
C: Me?
S: It was 100% you. I was trying to find housing…..to buy a new house….
C: ….and I was like “no, they’re all terrible”
S: Yeah, well, no, it was when I decided….. I finally gave up… I looked for housing for ages, I finally gave up and made a joke that I will live in my car. So then I was posting vehicles. I put a deposit on a camper van.
I remember you said, “you don’t know what’s behind the walls”. And I was so discouraged at that point.
C: That was the one that was built out…. it was old. [Camper van build outs are very prone to mold].
S: Yeah it was old enough that it probably would have been contaminated. And I didn’t know about extreme mold avoidance, I hadn’t read the Beginners Guide to Mold Avoidance. I didn’t know all the nuances.
I was so discouraged I was like, “stop telling me the vehicles are not good!” So then that led me to actually read the book [Beginner’s Guide] and go, “ohhh now I know what she’s talking about”. I bailed on that camper van. And then changed my plan to actually doing extreme mold avoidance.
C: But you were in the mold groups, I wasn’t just coming into other groups and saying things like that! That was an extreme mold avoidance group.
S: And I didn’t know that it was different than what I was doing [already].
C: So, we’re going back to that time [again for a minute]. Houses are so difficult to find around here. You had MCS and some mold sensitivities. When you’re in that extreme level of MCS, you’re so limited. Usually people end up choosing moldy houses.
S: We are avoiding new houses because of the offgassing….
C: ….and maybe some have fragrance you are ruling out so many options, even just a cross-contamination of a fragrance.
So you were in the mold groups and the van was an idea, that van was tricky, I’m glad that van didn’t’ work out!
Then you found the most amazing vehicle of all time…
S: I researched probably 15 different solutions – inserts for trucks, medical transport, then I thought, what about an ambulance? Then that led me to the term Campbulance. I was watching van life videos like crazy to learn how to do it. I thought the campbulance would be more sterile and well maintained.
I found one being sold by the Province of BC. The Province gets rid of them every so often. I did tonnes of research and moved into an ambulance.
C: Ya, it’s such an awesome vehicle.
This is another key area. It didn’t seem like you had that much brain fog at the time.
S: Oh, I did at the time.
C: Cause now you can see the improvement?
S: It’s not as bad as it was in the beginning, but I was having trouble at work….
C: This was a critical time, you did have less brain fog or more clarity [than others], you were able to sift through the information, organise the information that was in the groups.
That’s another bottleneck stage. The first bottleneck, is thinking, I’m already avoiding mold because I can smell it in other buildings. The second bottleneck is how do I make this happen. What are the options and the solutions.
Do you think that looking at the struggles of others in the groups now. Do you think there was anything different about you at that point?
S: I think because I’ve been doing this for so long, MCS avoidance. I deliberately made a career I can do from home. My life has revolved around [MCS]. I don’t know that I could have done this just winging it if it was my first time, as quickly as I did it. I already had a job set up….
I also have a brain that is good with spreadsheets. I had spreadsheets with all the different vehicle options, all the features that I needed.
C: You had places lined up, you had places with wifi, since you need to work.
S: Exactly.
I listed and downloaded all of the apps, like freecampsites.net that show you where you can boon-dock, where they can show you wifi signals, I just researched all the places I could go.
C: I remember you even had a spot in case the fires did come (this last summer). Which was a lot of research.
[But], you also didn’t get into the bottleneck where you over-researched and just didn’t do anything. Like this ambulance could break down, this van is moldy, this tent might not work…
S: I think I got lucky because I didn’t do it perfectly at first.
C: No one does!
S: I made lots of mistakes but it still worked anyway. I think it just works out, you just keep doing it and it works out.
C: I think I want to stick that point a little bit, because you were able to do that strategic thinking planning comparing and get to the solution in a reasonable amount of time.
S: I think it’s a lot easier to do that when you have a sounding board, someone who is a little more cognitively with it. Now I have a few facebook friends and I help be their brain.
C: In the beginning, there are not a lot of people, and that’s why I do this as a job, there are not a lot of people who have the bandwidth and time to help the people that are in the beginning who have cognitive difficulties. I think it’s a key time for people to get help with the decision making. Especially if they are worse off than you.
Once I saw you get on a roll with it, I was like, oh, you’re gonna be fine.
S: 20 years ago I would have needed my mom, I was planning my trip to BC to get well, I told her I need you to be my brain. I think if someone is worse they need someone to lay it out step by step for them.
C: And now that you’re at the stage where you have some experience, you’re doing a little better and you can hook up with other mold avoiders who are in that stage and you can help each other. That’s a lot easier to find because you can mutually help each other. In the beginning, that’s a lot harder to find, because you’re the one in need. And a lot of people get stuck there. That’s a tricky spot if you get stuck.
[On to] the ambulance! I don’t want to talk too much about the ambulance because I could talk a LOT about the ambulance. We need to find out more, if we can find out how this was built. I think this has SIPS walls or spray foam. It is well built.
S: I asked for the blueprints but never got them. I just know it’s well insulated. A refrigerated truck is similar.
C: I want to dig deeper and I know other people are looking into custom building. Yours… I wish we could dissect it. It’s not very new right?
S: It’s a 2009.
C: It’s not too old. Most trailers don’t hold up that long [to mold]. There’s the fiberglass types. I go through all the types that tend to last a little longer but they all have their drawbacks. Yours I think is made like the older Camplites, that have a sandwich laminated wall. Or it just wouldn’t hold up this long. Maybe in 10 years when it dies, we open it and rebuild more of them like it!
That’s another difficulty – finding a trailer that is offgassed. I bought a Camplite when I was starting out, it was metal-foam-metal. I thought this would be fine. This was 8 years ago. It was so strong with the offgassing, it blew my mind. It reeked like glue. It was a well-made trailer, but I wasn’t able to use it until it offgassed. I regret selling it, because once it did offgas I should have kept it for emergencies or traveling. I just didn’t realise what a gem it was.
There are other options, vans that don’t have wooden walls and nothing in them….
C: You actually made pretty quick gains…
S: I think the reason was that I spent 10 years in avoidance, and it was a pretty fast and short crash.
And this is why I knew it was mold, that mold avoidance is the reason I got well, because I spent a year in the Slocan Valley (in BC, Canada), which is as pristine as it gets in terms of MCS – no cell towers, I had the best water, the best air [in theory], and I still stayed stick for a year [after returning from Ontario], and then as soon as I did mold avoidance, within two months, I was like I’m going to go for a hike now. I went, WOW.
C: And then from there you got even better. So within the first two months… you started in Slocan, then you went to the Okanagan. Within two months you saw quite a lot of results.
S: I left in June and within two months I was slow hiking, by August I was feeling even better.
C: By now…. you started June….. it’s been 4 months.
S: It’s mid-October now, I’m in Idaho. The longer terms things are healing now. I had really bad psoriasis. My energy levels are even better. My diet and appetite are even better.
C: That’s so awesome.
Are you still sleeping in the ambulance.
S: I’m sleeping in a tiny house/cabin. That was built with MCS and mold in mind.
C: And you’re still feeling as good or better.
Yeah one sign of health is remembering my dreams and have lots of dreams, really good sleep, 8 hours. I have the best sleep now, I go walking every day, I work full time. We carry water, I can chop firewood. I can do lots of physical tasks I couldn’t do before.
C: Do you want to say what percent you are better?
S: 85%. That’s pretty subjective.
C: Yeah, some people would be thrilled with 85, and some people as they get better they will say they didn’t even realise there was another level of health.
I’ve also been sick for a long time and have trouble with those percentages.
S: I leave 15 % because I could do more intense hikes. And I also give it such a high number because some of the really scary things are better.
I can (but don’t) pump gas. I got diesel on my hands and brought it inside, and though, “oh, that smells bad”. And I was perfectly fine. For me that was a huge huge leap.
C: I don’t think people know I was as extreme as you, or close. I was floored by having someone else pump my gas [at my worst].
S: I went dancing and it was a room full of perfume – when I was really bad I would have been really sick after 5 minutes. In this case I actually danced for I don’t know, maybe an hour. Then I did get sick but I was able to step out and be OK. I’m not perfect where I can dance in a perfume room for 3 hours.
C: It’s [still] a lot of progress in a short amount of time. It’s taken me a lot of years to be OK around perfume. And everyone has such a different journey. It’s really hard to say how it’s going to go. Some people, their MCS disappears almost immediately, though they might not have been as severe as us from the beginning.
For people as severe as us, it’s not unusual that it’s going to take some time. Fast gains are always exciting though.
S: I think the one and only thing I wish the people with MCS knew, is that mold avoidance isn’t necessarily what you think it is. It took me years to realize it’s not what I thought it was. [Understanding the role of] outdoor toxins is HUGE. Understanding it’s not a smell. At least giving it a shot. I have heard a lot of people say I’m already avoiding mold. Which is what I used to say. Then realizing, oh, I really wasn’t.
I think the best way I can explain it, it’s not just your everyday average mold, it’s “super toxins”. And avoiding those is a bit of an art form, but it’s worth learning and at least giving it a shot.
C: I agree. What I see is that people with MCS and lyme are aware of mold. They are aware of the offgassing, the fragrance, toxins in the outdoor air. [All the toxins out there]. But some toxins are more destructive. If we can take out the bigger ones….
I will link to Lisa and Erik’s book, and Bryan’s book, I should add Julie Rehmeyer’s book as well, Through the Shawdowlands which is also very helpful. They talk about taking out the master toxin. Mold is one of the really key ones. Fragrance isn’t the master toxin. You won’t get out of this by avoiding fragrance.
I know for sure from watching this for 10 years.
Updated in Summer 2020
Related posts:
1. Regular-sized non-toxic prefab homes
2. Mobile homes on wheels for those with sensitivities
3. Emergency shelters for those with sensitivities
These are small and tiny houses (not on wheels) that are suitable for those with extreme sensitivities to mold and or chemicals.
Not all materials will work for all folks, that is why this article features everything from all wood, to all plastic and all metal homes.
I have natural materials on the list as well, like hemp and concrete.
These small houses are ideal to create a healing space away from conventional housing that is so prone to problems.
This post contains an affiliate link to a home sold on Amazon. This home was on this list before they starting selling through Amazon. Upon purchase, through affiliate links I earn a commission at no extra cost to you. This post is not otherwise sponsored by any of the companies.
For individual help choosing the best small home for your needs, or a review of a tiny house company not mentioned, you can contact me here for a consult.
Besonwood is a high-quality passive home custom prefab company. Their custom Thoreau Cabin home is 150 sq ft. The owner chose the stone facade but that is not a typical facade. They are custom homes so they can build any size.
Their predesigned wing is called Unity Homes. Their smallest house “Nano” (pictured) is 477 sq ft. Nano Shell packages start at $65,000, and for a complete house, it would be roughly $150,000.
They are wood framed with passive house design, made to high standards. This would not work for those extremely sensitive to offgassing as their walls include OSB and engineered wood framing.
The insulation used is Rockwool and cellulose in the model I saw (they have different wall systems to choose from).
This is a house that mold sensitive folks should consider due to their high-quality design, high-quality factory-built, and indoor factory conditions. This is at the top of my list for a reason, I would build with this company.
You still have to have planning and supervision on the site prep, foundation and the installation of the prefab components. Every detail matters for mold prevention.
The Holz100 homes come in all sizes from very very tiny, small and large.
The walls, floor and ceiling are all wood, no glue, no nails. The roof will not be all wood, there will need to be another roofing material there.
I have a more in depth review in the general prefab post.
I think this house is very promising but needs more investigation. If you tolerate wood there is nothing else in the interior.
To hit codes you will need to put exterior insulation on it. Exterior foam insulation would also be a fool safe method to prevent possible condensation within the air pockets of the wood wall. That is how I would detail it for mold prevention. This would make it quite pricey.
$35,000 BASE PRICE (CAD) for the 93 sq ft little module.
The metal yurt from Clean Air Yurts is 18 ft in diameter. The shell is made of galvanized steel coated in zinc. The door is metal as well.
You would need to build a foundation and choose materials for the exterior and interior, provide insulation and wiring and plumbing (if desired).
Though you could just leave it as a steel structure. The yurt can be assembled in one day and can be taken down and moved if needed.
Metal walls are very difficult to insulate in cold climates. In a cold climate, you would need a perfect airtight insulation. See the section at the end about exterior vapor barriers in cold climates. Metal houses can work well in places where you don’t need insulation or where you don’t use heating.
In some very dry climates, you can get away with loosely fit foam insulation but you would want to be able to check on that and make sure there is no condensation behind it.
The cost of the metal yurt is 10K
These Grain Bin Homes are also 18 ft in diameter and made of galvanized steel. There is room for a loft and it has louvers that can collect rainwater if desired. Other options include solar panels.
It does not come with options for interior/exterior or foundation, so those would be up to you.
The homes are around 10K but there is a big discount for non-profits who are purchasing them.
Same as above section regarding metal walls – tricky to insulate in heating climates.
From Out N’ About, a company that rents out treehouses, sells plans and parts, this 16′ Treezebo Hexagon could be a great non-toxic home.
The plans for the treehouse are $450 and that includes a 3-hour consultation. The metal parts are $2000-2500 and the wood would come to around 5-10k, not including materials for wiring and plumbing.
I like this simple option if you don’t need insulation. Using a rot-resistant wood and no need to worry about the foundation type simplifies everything here.
This can be a mold preventative option.
The basic kit for Arched Cabins includes floor plates, ribs, ridge beam, standard R13 insulation, Super Span Roof Paneling, trim and fasteners needed to assemble the cabin.
Arched Cabin kits do not include the foundation, installation, interior, end caps, delivery.
What I like about arched cabins is that there could never be any leaks with this one-piece roof/siding.
In this design, you can use spray foam insulation (with or without rigid foam) without worrying about exterior leaks getting in behind. Spray foam, while it does offgas, is a vapor barrier and the best bet for insulating metal walls in heating climates.
Either closed cell (2 part) spray foam is used to form an airtight vapor barrier in any climate where you heat, or not quite as foolproof is rigid insulation installed with canned (1 part) spray foam).
This is a great system for preventing mold. You do not want permeable insulation against metal in any heating climate.
The large overhangs are also superb protection from rain over the windows and doors on the ends.
The 12×12 kit is $2400. This is a simple, mostly metal kit that you could then customize to be chemical-free on the inside.
You can see a video tour here and you can check one out on Airbnb.
These cool Intershelter domes are easy to transport and assemble and have a lifespan of 30 years.
The larger domes are made of a fiberglass composite material that the company says does not emit an odor. Some sensitive people say fiberglass needs some time to offgas (1-2 years or more) and others find it ok fairly soon after production.
The small domes are 14 feet and are made of ABS plastic, which is a really safe plastic (the same plastic the LEGO is made of). This one they say has an integrated foam component.
I would look closely at the details on the panels that have integrated foam. You would want to make sure this is not likely to leak.
If this is done well this would be much easier than trying to put foam insulation on the inside of the one-panel fiberglass domes yourself.
The integrated foam would be ideal for heating climates (cold climates).
The domes start at $7,500 for the 14′ model in 2017.
Installing foam in the larger domes with an exterior vapor barrier is not simple in heating climate. If you are in a tropical climate this might be ideal.
A similar dome, the Intergalactic, is also fiberglass, and the insulation is integrated.
EverBlock makes plastic blocks that fit together like lego. You can make a simple structure out of these.
It’s a safer plastic than fiberglass that is much more tolerable for the chemically sensitive.
There are a few designs that are using metal framing with a plastic body. I find this design extremely promising.
The Coodo above is made in Germany and can deliver all around the world.
A similar company, AluHause is American, with a show house in Palm Desert.
The downside is that fiberglass does offgas and won’t work for many sensitive folks, at least not right away.
Both have the potential to be very waterproof and mold resistant designs. Neither one gives too much away on how it’s built exactly, so we cannot evaluate it in great detail.
Just like when looking at larger prefabs you have to go through the reconnaissance process outlined here.
The Coodo is 61K British Pounds for the base model.
Another similar model is the Haus.me which I go into more detail on in the prefab article. This one looks to be a different type of plastic, not fiberglass, though they don’t say which type. They claim that it doesn’t offgas.
Leisure Cabins bare bone wooden cabins are made of solid wood. I see some OSB in the subfloor but that could be avoided. Opt for solid wood for the roofing as well.
There is no insulation so they would be difficult to live in in extreme temperatures.
It does not include roofing shingles and roof prepping, stains, railing, foundation and deck or windows. You do your own wiring, plumbing, and systems as well.
This version is a thin wood wall, not very warm. And when you start to insulate something like this you start to get into a complicated design.
In that case I would prefer to go back to a prefab like the Unity Homes on this list which already has a well thought out wall system, or even design a house from scratch.
Trying to make one of these kits work with insulation is working backward from a plan that won’t likely come together in a mold preventative way in climates where heating is used.
It is $6500 CAD for a 14 x 14 foot cabin. They are produced in Canada.
From Backyard Buildings in Maine, these tiny houses are a good deal. They are custom built. This one pictured is from a member of the EI groups on Facebook and I have her permission to post about it.
The house is made of local wood, non-fiberglass insulation, low VOC adhesives, a woodstove (but you could use electric heat), wired for on-grid (but can do off-grid as well), cedar siding, metal roof, and plumbing.
This does become a complicated system to design when you add insulation.
When I tried to work with this company, it was difficult to communicate with the builders (because of lack of technology/being Amish). They were mixing some traditional building with some more modern techniques like adding exterior foam insulation and I didn’t think it was mold-safe or detailed right.
They can be moved though they are not on wheels. This one is 400 sq ft and was only 14K. I would only get a shell if buying something like this so that you can detail it yourself.
When buying a shell you also want to make sure it has a rainscreen if you are going to insulate it, otherwise you won’t be able to build that out properly.
For a thicker wood wall look at a company like Montana Mobile Cabins. This true round log cabin does not use insulation.
I much prefer this simple design than to try and insulate a wood framed cabin. This is a much safer bet for mold prevention.
It’s not perfect as I have heard of condensation in log cabins, I would consult with a building science expert on how to make this work in your climate.
I like the thick square logs too. I like that they would fit together well. In theory this might create a more airtight assembly which might help prevent moisture and condensation issues.
Confederation Log Homes above makes custom prefab log homes with square-cut logs. The company has been around for a long time.
This is the first log home company I would look at due to their extensive experience.
The Nomad Cube is a promising little metal SIPs house. It can be built out to be very non-toxic.
Metal SIPs make up the main walls and roof of the house and are made from laminated steel-EPS white styrofoam-steel. They are essentially 0 VOC and extremely resistant to mold as long as the panels stay laminated together and assuming there are no leaks into the panels.
The smaller Nomad Micro has been redesigned since I originally wrote this. That one is no longer a SIPS house.
The Nomad Cube costs $38,800 USD. It is 13 x 13.
You need to add: shipping (From Vancouver BC), platform/slab/or piers, installation, wiring, heat, plumbing, hot water heater, roofing membrane, interior walls, baseboards, shower door, ladder/stairs, fridge, range, and hood vent.
My most sensitive friend tested the SIPs and thought they were good. It is possible to complete the interior with non-toxic materials.
The basic design of this house is metal framing with metal SIPs. It appears in one of their videos that there is plywood in the base, which I would change.
You will need to have a building science expert review this design and help with the details along the way.
I consider this one of the most promising designs here. It’s the first option on this list I would look into for something really small and simple.
Metal SIPS homes work really well for mold and chemical sensitivities.
You can also make your own SIPS house easily and fast. This one below is made with Structall Building Systems panels. Another brand that I have seen sensitive people use is Permatherm.
These are also metal-EPS foam-metal and have an internal locking together system that allows them to quickly snap together.
In this design the panels are fully structural elements, there is no additional metal framing. The panels make up the walls and roof.
To create a long term structure you would use siding on top of the SIPS and pour a cement slab to the same standards that you would use on a house.
But quick and dirty, you can throw up these panels fast and get away without siding if you don’t need it to last forever.
This is the fastest and safest (for both mold and chemical sensitivity) option on the list.
The company Boxabl has created a metal SIPs house that has caught a lot of folks’ attention.
The main reason it has gone so viral is that it promises it all – fast, easy, cheap, resilient, and healthy.
First, is it good for chemically sensitive folks?
Yes, the basic structure of steel/foam SIPs is very safe for those with chemical sensitivities. That part has practically no offgassing.
They also use MgO board on the interior surfaces which is generally safe for most people with MCS. It’s not clear how that is attached, it’s likely glued on, which could be a problem for offgassing.
The flooring appears to be glue down vinyl, though they have described it in different ways. The countertops and tabletop are laminate. And the interior cabinetry is conventional. These three elements will contribute to offgassing of some VOCs, plasticizers, glues, and formaldehyde.
At this time it cannot be customized and it includes all the interior finishes other than the bed and sofa.
Even though it would be quite easy to choose a healthy floor and cabinets, it would likely be difficult to remove the already glued down vinyl.
Is it a mold preventative design?
In general, metal SIPS are very resistant to mold because as long as the wall remains laminated they are immune to condensation problems. The waterproofing will depend on how well the seams are connected.
There are a number of concerns I have with this house:
Is this a reliable company?
Still in development
Well, I don’t think we know if this is a reliable company yet. As I discuss in my general prefab post I never go with the prototype of a prefab. They commonly have problems.
There could be situations in which we know a lot about the company, the construction details, and the testing of the prototype, but I don’t see enough information here to be confident.
The company needs to raise 10 million dollars to be in full production, and right now they are still raising money. They are not yet at production stages.
Inconsistencies
On the fundraising page it says “early investors get a discount”. When someone asked what the discount is they responded “It is possible there will be a discount. We haven’t announced it yet.”
In one of the videos, the rep states that you could install this without a foundation or permit. That sounds like very ill-advised advice.
It does not seem like the reps actually know what the floors are made of.
Hemp House Pods – a simple 8 x 12 structure meant to qualify as an ADU (without a permit) is made from hemp and a wood frame. Hemp may be mold resistant in certain climates.
I would have this reviewed just like all the others. I would use huge overhangs and I would look more closely at a foundation type that does not wick moisture up.
The cost does not include plumbing, electrical or the deck.
The houses are 15K and they say they go up in a week.
I reviewed the AirCrete dome for mold resilience and I have a few thoughts on it. (Note this is different from AirKrete with a “K” insulation, though it’s a very similar material).
AirCrete domes are made of a mix of concrete and a foaming agent. You can use a natural dish soap like 7th Generation.
They were originally used in tropical settings and I do think they might this is simpler in climates that don’t require heating.
I do not like any of the designs that have multiple domes coming together creating valleys where water will not drain well. In some designs, debris is even accumulating in those valleys. I would only do single domes with as steep of a slope as possible.
No valleys where water and debris collect and soaks in. This is always best practice for mold prevention in houses.
The steeper the slope the better it will shed water.
The exterior is coated with waterproof exterior stucco and then acrylic or similar concrete sealer.
The coating would have to be waterproof which creates a dilemma in heating climates.
If it’s waterproof that is usually an exterior vapor barrier, which can cause condensation and mold in climates where heating is used. This is fine to use in climates where only cooling is used.
I might put this whole structure under a second rood, like a carport (or a souped-up metal roof like this house has). That way you don’t have the conflict of the need for a waterproof but also breathable sealant on the exterior of the dome.
You may also consider a sealer that sheds water but is breathable – a layer of concrete stucco sealed with sodium silicate might work. Just like polished concrete which is vapour breathable but should shed water. Consult with a building science expert to work this out.
Conventional wisdom is that concrete cannot mold because it’s not organic. As a mold sensitive person, I would say every basement, most slabs, and almost every concrete building in the tropics shows otherwise.
Mold can grow in anything porous, I have found.
Climates that are hot and humid should use AC or a dehumidifier in any concrete building. AC acts as dehumidification.
It can take 2 years for concrete to fully dry and in humid countries that don’t use AC, concrete goes musty fast.
Many people might not notice this low level of mold but I can smell it and mold sensitive people do often react.
I’ve stayed in many simple concrete builds in the tropics.
It’s also incredibly important to detail the slab right for mold prevention. Slabs are very prone to going moldy in all climates and are rarely detailed properly.
Because slabs are made of concrete and the dome is concrete you also have to take extra precautions with the slab and site details to not have wicking up of water from the ground up through the structure. This could easily happen in rainy climates.
The final flooring over any slab also needs to remain breathable to the inside in best practices for mold prevention. If the slab does take on water through wicking or through water coming in through the sides it needs to dry up.
Only polished concrete, tile (including stone tile), or earthen clay floors should be used as the final floor.
I think this dome would work for many people with MCS.
Admixtures are used in the concrete, you would want to check those out.
The foaming agent can be a non-toxic soap, if you tolerate one of those.
The interior can be finished with natural plaster which does not contain additives.
The exterior finish needs to be looked at carefully, synthetic stucco might not work for everyone who is chemically sensitive. That won’t work in most heating climates anyway. Sodium silicate is considered safe for the chemically sensitive.
The slab would have the same concerns as all slabs. You don’t have to use rigid foam in the slab in many climates, but you do need a thick vapor barrier like Stego. It needs gravel underneath and proper grading.
A polished concrete or tile floor works well for chemical sensitivities.
You can find the workshops and the tools needed to create the concrete foam mix at DomGaia.
I have not been a fan of container homes in the past because the exterior metal envelope creates a really tricky situation for condensation is every heating climate.
More on that below, but if you are somewhere where you only use AC or no heat or AC this can be just fine.
When I saw that a company is making exterior insulation for shipping containers this changed my mind on the topic. The foam contours to the container and insulating it on the exterior eliminates the condensation issue.
You will still have to detail around the window and doors, and make the steel envelope airtight (I would try to weld all seams) but I really like this idea.
A prefab house that has a metal or fiberglass shell that does not have a rainscreen system is extremely difficult to insulate in most climates where houses are heated. This includes container homes.
“In a cold climate during the heating season, moisture vapor inside a building is driven outward into exterior walls. When it reaches a surface that’s below the dew point, the vapor condenses into a liquid.” (source).
In this case that “surface” where moisture in the air condensates is that metal or fiberglass shell.
To try and work with this problem you need airtight insulation. This could be 2 part closed-cell polyurethane spray foam insulation. This offgasses too much for most people with chemical sensitivities. It also causes the challenges of exterior leaks going undetected. Arched Cabins has a nice design because there are no seams or permeations.
The second strategy is to use rigid foam insulation and make it airtight. This is also tricky. Foam can be taped or sealed with caulking or 1 part canned polyurethane spray foam, but it’s difficult to keep it airtight. And any gap of air behind the foam can have air with enough moisture to condensate in some climates.
Options:
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I have updated this post after having spent 2 years of close to full-time camping.
The focus is still on avoiding chemicals, but I am adding more unusual camping equipment and techniques for avoiding mold, updating new gear I really like, and some new tricks.
This post contains affiliate links wherever the brands I like have an affiliate program. Upon purchase, I earn a small commission at no extra cost to you.
I bought a pop-up tent as my first tent. I went for one of the cheapest options here just to get started quickly. I was able to use it after one week (with the doors all open at first for air) but it was about 1 month before I found it offgassed the chemical smell, and I could close up the doors. I was super sensitive at that time.
A number of brands have pop up tents in this style which are super easy and quick to put up and have a decent design in terms of the amount of ventilation (more on the style I prefer with ventilation below).
Mine leaked in heavy rain so I don’t like this style of tent, other than the fact that it is very easy to pop up and if you get a good tarp over it you will be waterproof – I always put a tarp over tents now anyway, more on that later.
Anyone super challenged with putting up tents might want to start here.
For heavy rain, a tent with a really good rainfly is needed that comes down almost all the way to the ground like many of the REI or MEC brands and this Backpacking tent (pictured left).
I used the Winterial version of this style for many months and was very happy with it. (This brand claims no flame retardants).
When it comes to tents on the ground, this is the main style I look for because of the good rainfall, which keeps it more waterproof.
Having mostly mesh on the inside also reduces your exposure to chemical offgassing and helps to prevent condensation on the walls.
Technically you don’t need a tarp over it, but I always add one. Water that soaks the tent walls will then soak anything that is touching the walls inside. The tarp is also needed so you can get in and out when it’s raining.
I just don’t trust any tent enough to not put a tarp over top. More on setting up tarps later in the post.
Sometimes the rainfly smells stronger than the tent and sometimes it smells less. Sometimes a super beefy tent bottom is the hardest part to offgas. It depends on the brand.
Some who are trying to reduce exposure to chemical offgassing wash the tents to remove some of the treatments, but this also removes some of the waterproof coating. That can still work if you have a good tarp over.
The more mesh you have the more airflow and the less exposure to offgassing.
For stealth camping on patios and balconies of hotels or Airbnbs I have used a one-person tent like this Winterial brand. I also like this Tenton brand (I like that it comes with straps to strap it to a camping cot below to raise it up).
You can also look for tents called bevy tents.
I have tried just a mat with a mosquito net over it (this one is not treated with pesticides), and I have also just strung up the just the rain fly (with no tent) over a camping cot and Thermarest if there are no bugs.
Otherwise, you can cut out the bottom. Never put a tent with a bottom right over outdoor tiles, bricks or concrete for long, you will have a recipe for mold fast.
You can put up a tent on top of a camping cot like in the pictures of the Tenton one person tent linked to above. But to keep a low profile I prefer to use a camping cot and then string up the rainfly or mosquito net so it does not go higher than the balcony rails.
If you have a stable place and are not on the move, I like these garage/deck tiles to lift you off the concrete. I’m trying them out now.
Make sure you know how (and that you can) put up your tent alone (as well as set up other supplies like a stove) before you get to the campsite. I have shown up to campsites with tents that are defective or missing parts more than once, so I would do a trial run for that reason as well.
For those who are disabled and limited, I made this video on Camping for Those Who Can’t Camp, to try and give some examples of how camping might still be possible for you.
I like putting tents in the sun to offgas them. Smell them to test, and also touch them to make sure they don’t cause skin irritation. You may have to test them by sleeping in them to test for tolerance.
There is no consensus on which brand is the best for those with chemical sensitivities. Everyone is so different, no tent is perfect, and for some less sensitive there might not even be a big difference between the brands. You have to test them out for yourself if extremely sensitive.
For the mild-moderately sensitive:
For the moderately to extremely sensitive:
Silicone treated tents might be more tolerable for some, others may prioritize avoiding flame retardants.
If you are too sensitive for any of these brand there are more options further down in this post for those who have to go more extreme.
Some canvas tents do not have flame retardants.
Cuben fibre from what I have seen is FR-free.
I have not found any evidence that many flame retardants can be adequately washed out, but it can’t hurt to try.
These tents have the benefit of insulation, and the aluminum coating reduces offgassing. They don’t do well with humidity inside the tent if there is a warmer inside.
WeatherHyde tents are insulated and the foil on the inside will also block most of the VOCs from the fabric on the outside. They say you can sleep in them down to 0 degrees Celsius. They are 269 USD. They do not have any mesh for ventilation which I imagine would be quite the problem for condensation and I do not know how you would get fresh air.
The Shift Pod is another version of an insulated aluminum tent made for Burning Man. The benefit to the aluminum on the outside is it’s reflective of sun and heat. I would think it would have similar problems with condensation in most situations. It’s pricey at 1300 USD.
For 18 USD you can get this aluminum lined small sleeping tent (that might work for balcony sleeping or in an emergency, otherwise it’s difficult with a lack of ventilation). The aluminum on the inside is more tolerable than the usual plastic.
Others have made homemade tents with materials they can tolerate like Tyvek, Reflectix or XPS sheets. You can also make a more typical tent from untreated nylon.
More info on that in this post here.
Some folks who cannot handle the chemicals in the synthetic tents have tried canvas tents.
Some companies people like are Reliable Tent, Kodiak Tents, Davis Tents.
Are they Mold-Prone?
These do not hold up well to rain and high humidity and I would not use them in rainy or humid conditions nor expect them to last very long at all.
I have seen canvas tents, specifically, Davis tents hold up for quite a long time in a dry climate and with a woodstove inside. It can take rain and even snow, as long as it can dry out. For long term living a gravel floor or a raised up wooden platform is best.
Hemp Canvas
For those who don’t tolerate cotton or who want the tent to hold up a little longer than cotton canvas, you can make one out of hemp fabric, like this one. You can expect cotton and hemp to last a short while in dry non-humid climates where you are expecting very little or no rain for a while.
If you are making your own tent out of canvas or nylon you can use the tube structure of a conventional tent and build it around that.
Wall tents can be canvas or conventional nylon/polyester. They have straight walls and are generally larger. Barebones makes a nylon polyester wall tent. Often this type has more weather poofing and will have flame retardants because they are set up for wood burning stores.
This can be a good solution for a longer-term camping tent. Though you should take care to keep the base dry (cut out or raised up) if you want it to last.
I bought a tarp for underneath to keep dew from getting the tent wet from below (also called a footprint), and later I added a tarp for over the tent to stay dry.
At first, the bottom of my tent stayed nice and dry with the tarp underneath. I would take out and turn over the sleeping mat every day.
If the bottom of the tent gets wet you will want to dry it in the sun within 24 hours (flip it and then put it back and maybe move spots).
You can use the footprints made for underneath tents but tarps are generally cheaper (your tent may come with a footprint).
You want the tarp underneath to be a little smaller and tucked in so that is is under the tent. No water should get between the two. Some people tuck it and then raise it a little with sticks or rocks so that no water gets in between. I tried that but in the end tent bottoms still went moldy on me if I had damp soil.
Putting a tarp overtop helped a lot. I found regular tarps from the hardware store has a strong smell but offgassed within a few days.
I now use a silnylon tarp which has a less offensive odor, and is more durable, but is more expensive. Over most tents, you need 12 x 10 or 12 x 12.
Some people find they still do have to move the tent every couple of days due to condensation or the earth going funky underneath.
Mold Avoiders! Keep a backup tent that is offgassed in case of mold or damage to your primary tent. Keep backup gear especially if you are out in the wilderness, if you need geat to offgas before using, or you cannot easily drive somewhere and buy new gear within one day.
Generally, you string up the tarp up in an “A shape” so that it’s touching neither the tent nor the ground, you can also string it up with a shed slant like the photo above.
Some people dig a small trench around so that the water that drips off does not go towards the tent.
Without a tarp, I had a lot of problems including saturation of the tent and water coming through especially where anything was touching the tent. I would not attempt camping without a tarp overhead again.
In a major storm, a larger tarp overhead helps, as well as a deep trench, and if things are going swampy you need to raise it up. I have used XPS sheets to raise up a tent in a storm before I found the Cot Tents.
After throwing out many tents and then moving on to cutting out the bottoms, I finally found what seems like the perfect tent: the Ozark Trail Two-Person Cot Tent. You might find it on Amazon, but at times I can only find it available at Walmart Canada.
This is an integrated camping cot tent (pictured). This is off the ground so the bottom will not mold. You might find the one-person version available in the US.
This had a very low odor rainfly and a brilliant design with the rainfly coming down way past the cot to protect water from getting in between.
This is the best design of a tent I have ever used, though it’s flimsy and broke on me when I took it down. It is assumed here that the Prop 65 warning here indicates the flame retardant “Tris”.
Although I didn’t like the more common style of tent cot (I had trouble with ventilation and even dangerously spiked my C02 levels one night).
It was the Kamp Rite brand that I tried in this style. The Camp Rite brand does have a two-person version.
I quite like the Tenton tent that is made to strap on to their XXL camping cots.
You will, as always, want a tarp over this whole set up since this rainfly does not come past the cot (though on their website they sell a larger rainfly which would).
These cot tent brands are coming and going. I’m not sure if it’s a lack of demand which is a shame because for mold prevention these are ideal.
Other Raised off the Ground Tents
The tree tents look interesting, as they are raised off the ground, but you have to keep in mind these are really just for sleeping as they don’t look very conducive to hanging out all day. I wonder how much they sag in the middle, and they are not as easy to put up.
For those who are less picky about their sleeping environment resembling a regular bed, the hammocks with nets are interesting options that are affordable and easy to travel with.
Cot Tents are Bulky
While I would never want to go with anything other than the raised off the ground tent again, this won’t work when I travel overseas. When I travel I need to fit a tent, sleeping mat, and sleeping bag into a duffel bag.
The sleeping mats I use are huge and unless I can send a tent ahead I would have to go back to cutting out the bottom. I would use plastic bags to encase the sleeping mat, instead of the thick tarps I mention.
Cot Tents are Colder
It is cooler when you are raised off the ground. But I don’t find it any worse than cutting out a bottom and using a camping cot (in fact I find it warmer than tents with the bottom cut out).
Flame Retardants
Ozark is a very tolerable brand for MCS. I don’t like the flame retardants they use. I have not seen a flame retardant free brand in this style.
For those doing mold avoidance or living somewhere very damp, you might want to go with the more disposable option.
Expensive tents from REI and MEC tend to pack smaller and lighter and should be higher quality, however, if they do go moldy it is a bigger loss.
On the other hand, if I am traveling with a tent I want one that’s not going to break unexpectedly as many places around the world do not have stores that sell tents. Check also how much wind and rain they say they can withstand. You pay more for quality wind and rain protection.
But all of that said, I would never spend more than 150 on a tent unless I’m sure it’s going to last me a long time (like the ones raised off the ground).
I started with the Lightspeed air mattress made of TPU, which is the one the most sensitive to chemicals use.
It offgassed quickly (2 days in the sun) and felt comfortable. It’s good quality, but I had back problems with it. This can happen to some people on air mattresses.
Many with chemical sensitivities prefer the Intex polyester air mattresses.
Other very sensitive folks have tolerated the small air mats. I was very impressed with how little this one smelled (less than the air mattress), and it’s a WAY better option to travel with, but I did not find it comfortable enough.
Someone much more sensitive than me recommended the Klymit Static v which comes uninsulated and insulated (with what looks like polyester fiber, not foam).
Go with the simplest, most compact option that is still comfortable for you.
I ended up buying the thickest Thermarest instead and LOVING it. This is as comfortable as a bed to me, though many people put Thermarests over a camping cot, that seemed excessive with the MondoKing (though cots can also help you get off the ground which is a benefit when you have cut out the bottom or are preventing mold under the bed).
I’m not that picky about beds so I was surprised that the airbed hurt. The Thermarest has a decent R-value to keep you warm, the more insulation you have under you in the cold the better.
The MondoKing is very comfortable and I usually wake up forgetting I’m in a tent. It has polyurethane in it but it offgassed quickly in my experience. I used it after 2 days of airing out (not ideal), in one week I found it to be really good, and one month to be near odorless to me.
This is a super good mat for a trailer or other tiny home as well. It does not contain flame retardants.
I bought the repair kit for the Thermarest as well because this is going to be my main bed in the trailer, I also carry the repair kit when traveling.
I still prefer the MondoKing, but another good and more affordable (but thinner option) I use is the Lightspeed version.
When it was hot and sunny (and I was not self-contaminating) I had no problems with condensation if I turned it every couple days and some days left it standing up to air out.
You will want to flip or air out your sleeping bag as well in the day to prevent mold.
As it got cold and I moved it into a trailer it became very challenging to keep a sleeping pad dry and mold-free. It needs to have slats underneath and a waterproof cover without a doubt in a cold or damp environment.
I wouldn’t recommend leaving this on any flat surface without a waterproof cover anymore. As I got more sensitive I was not able to keep this clean without an encasement.
If you are very sensitive to mold, very unmasked, or detoxing through your sweat, encase the sleeping mat right away. You can use plastic but I prefer these thick aluminized tarps as they also block the smell.
I used those tarps if I needed to block the smell but if I just needed to encase it I used contractor bags that are thicker than the usual garbage bags. I taped it airtight.
For the ultra-sensitive to chemicals, an aluminized Thermarest is the safest camping mat.
People usually go with the solid foam or the small inflatable ones as they pack much smaller than the deluxe one I bought (and these are more affordable). They offgas less as well.
You can wash these unlike many of the other options. Some even pour boiling water on them to clean them and kill bacteria. You can’t do that with all camping mats.
I like this style of camping cot the best because it packs really small, it is relatively flat, works well with a Thermarest over it, and it’s low to the ground but high enough to have airflow.
I never put a camping mat straight on the ground anymore. I always want that airflow under the sleeping mat (if you are not using an integrated cot tent).
I would not say this style of camping cot is easy to take apart and put back if you are physically disabled.
The Coleman polyester camping cots do not have a water-resistant coating so they may be safer for the very sensitive.
I’m extremely pleased with this Teton sleeping bag which is warm and offgassed after sitting in the sun for a week or so. I never even washed it.
I used this in the summer and some days it was too warm.
Many who are super sensitive to mold and chemicals use the Suisse Sport Alpine sleeping bag.
Sleeping Bag Liners
Others like a silk sleeping bag liner which keeps you warm and keeps your sleeping bag cleaner. It is much easier to wash a liner than the sleeping bag. I’m using this silk one and it’s quick to dry (surprised by how chemically it smelled, needed more washes than most fabrics).
You can also make a liner by sewing a queen flat sheet in half. You can either use a liner to get inside of first or to encase a blanket. This will keep the sleeping bag good for longer. The polyester liners can work too.
Blankets instead of sleeping bags
In warmer weather, I skipped sleeping bags and used heated blankets as my only blanket. As I started to detox through my sweat things got trickier.
Now I like a warm but washable option like these Pendleton Blankets. But, when it is very cold, a sleeping bag is really the warmest option.
I use these AmazonBasics polyester sheets. But there are specific sheets for Thermarests and other brands of sleeping mats. They are also polyester, the only difference is they are fitted exactly for the Thermarest.
You don’t want any cotton in your tent – it doesn’t do well outside for long if it’s humid, and it’s terrible when wet.
I bought a polyester camping pillow which is small (and it has cotton on the outside!)
I use waterproof pillowcases to prevent mold which I aired out and washed before using. They do smell at first, but polyurethane coating does offgas (to most people’s standards).
I have tried lots of camping pillows from the air and foam ones to the polyester ones, to just using a towel.
Someone super sensitive recommended the inflatable Klymit Pillow X.
You have to figure out which is the most comfortable for you. Some are very small. The air ones can be easy to roll off of. A towel is easy to wash if you need to wash gear often.
I keep backups of everything.
I use a heating blanket in almost every climate. I thought the biggest problem for me would be stabilizing my temperature, but that ended up not being that difficult at all.
This is the Sunbeam heating blanket I use. After going through a lot of these, the trick is I want one big enough to cover me and I want the 10 hour shut off not the 3 hour shut off, to keep me warm all night.
They are challenging in how strong they smell when new and since they can’t go in a dryer they can be difficult to clean in cold weather camping.
I encase my current one in these liners and wash the liner every 3 days.
For those concerned about EMFs you can use this to heat the tent without putting in on your body. It won’t be as warm, but it is likely safer than a stand-alone heater in a tent. Or, the fancier and supposedly healthier option is an infrared mat.
This 60-watt heated blanket (the smaller throw size) will run for most of the night off this solar kit. I always have an extension cord running to my tent. A small heated blanket tucked into a sleeping bag provides a lot of warmth.
I have set up many a small heater in a tent. I check the wattage and if it has temperature control (I make sure my tent is big enough, note: read the tent dimensions carefully, they run small).
It’s safer to place the heater up on a small table or round of wood to keep it from knocking over or blowing directly onto something that could melt or burn. I make sure my tent is big enough to accommodate a heater with lots of space around it and it has an auto shut off when it falls over.
I use this little Honeywell heater because it’s super low wattage (250 watts).
I find it easy to accidentally shove this when sleeping and it can turn towards the tent fabric easily. That is just one reason why this is not technically recommended. It is a fire risk. This is what I have done, but I cannot officially recommend it.
If my tent is on the ground and I have a thick Thermarest, I can be warm enough with a heated blanket and that little heater down to 5 degrees C. I don’t sleep well when I’m cold, but everyone is different, so you will have to work out those details.
For the AC you will need to cut a hole for the exhaust and seal with tape around it.
If I put anything electrical in a tent I make sure I have multiples layers of protection from getting wet from above or flooding from below.
Use heaters, heating blankets AC or woodstoves at your own risk of fire or electrocution. They are not recommended for tents.
Here is the longer version of my Amazon visual list of my Favorite & my Unusual Camping supplies I bring with me on a Sabbatical.
(See the comment box on each image to see my notes on each one).
Corinne Segura is a Building Biologist Practitioner with 6 years of experience helping others create healthy homes.
I spent 2 years living outside in tents in order to bring down my chemical and mold sensitivities and get back into regular housing.
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This post covers converting a cargo van into a camper for those sensitive to mold and chemical offgassing.
I will focus only on a few key areas:
Building a camper that will be both mold-free and chemical-free is tricky!
Keep in mind a cargo van can be anything from a metal box with a bed to a fully decked out camper with a stove, fridge, sink, heater, AC, and even a full bathroom.
I recommend all of the products here, some products have affiliate programs and some do not. Upon purchase, I earn a small commission through affiliate links at no extra cost to you.
For assistance with converting a van with materials that are healthy for you and mold preventative, you can contact me here.
If you are not sure if you can tolerate the system for mold preventative insulation, I recommend getting in touch before buying a van.
The most important aspect of creating a mold-free camper is the insulation.
Here is the key point: no water vapor can enter the wall cavity, in most heating conditions, this means no air can enter behind the insulation.
With exterior metal walls, as soon as you are heating the van to the point where the exterior wall will hit dewpoint, you have a serious risk of condensation and mold in the walls.
So again, to keep it simple, no water vapor and no air can enter the walls if you plan to heat your camper when it’s cold.
Ideally, no air at all should be trapped behind insulation if you want to be extra careful to prevent mold.
If you are in a hot or tropical climate where you don’t heat you will not have this problem of the exterior metal causing condensation.
Camp Like a Girl, a book about converting a van, had a number of flaws and misleading instructions.
The writer uses some XPS and some EPS insulation. XPS is a vapor barrier (meaning no water can pass through 1.5 inches), and EPS is not.
Using XPS foam is one option to insulate your van. XPS or polyiso with foil backing are usually tolerable for most people with MCS.
However, just the foam on its own will not be airtight. You need canned spray foam to fill in the gaps if that is tolerable for you – the thorough system to prevent mold that is working in vans, and was reviewed by a top building science expert, is to fill in the area behind the foam with spray foam and squish it in, leaving no air behind anything.
You need to fill in all the crevices that are not big enough to take rigid foam with spray foam as well.
One part canned spray foam is not chemical-free, but I have found it odorless once cured. You will have to see if it works for you if you are sensitive to chemicals.
Handi-Foam is the safest one, as it is GreenGuard Gold certified. Great Stuff will work for many people. This method involves a lot of canned spray foam.
You can also buy one-part in larger quantities, I am currently testing out this DAP liner to attach foam to walls. They claim this is closed cell foam.
The rigid foam also then needs to be riveted to the frame.
I would not recommend the method in Camp Like a Girl of putting in EPS and not sealing it – this leads to condensation. Because she barely heated the van, and had hot temps in the day, this did dry out in the day and did work in those conditions.
Any foam with air behind can be a problem when heated. Breathable insulation is even more tricky. A few cold days in a row and this will start to be a problem.
A good way to go about it – if it’s warm enough – is to sleep in the van empty and slowly work on insulating and building it out. The other option is to get it all done and then wait for it to offgas.
Rigid Foam in the Bed
Some have used insulation in the bed platform to keep the bed warm. I would be concerned here with flame retardants in the foam, and putting a bed on a flat surface is a no-no for mold.
In the bed section, I discuss how to use insulation under the mattress without causing moisture and mold.
Spray Foam without any rigid foam is, in theory, your safest bet for preventing mold. The foam will get into every crevice and form an airtight layer that will prevent all moisture from getting into the walls.
Two-part spray foams are much riskier than the one part canned spray foam discussed above.
The best spray foams are Heatlock Soy line at Demilic and Icynene Proseal (both GreenGuard Gold) (closed cell). Both are polyurethane foams, from reputable companies that are usually easy to source.
A reputable and very experienced installer is more important than the brand, as that is where the process goes wrong and can cause it to fail to cure properly. This causes major offgassing that may not stop.
The DIY kits for this type of spray foam are a definite no. And it must be closed-cell spray foam, which is a vapor barrier.
I recommend these to healthy people who are set on spray foam. I don’t usually recommend them to people with MCS because of the possibility of prolonged offgassing.
The companies say they do not offgas, but I hear many many stories from moderately sensitive people that this does offgas noticeably in buildings. A small sample may air out quickly, but test this in a building before using it.
At least two years (if this is installed correctly) may need to be scheduled into offgas this for the moderately sensitive. If not installed correctly it’s a goner, you’re going to be scraping out the whole thing.
If you are mold sensitive but not chemically sensitive you could consider this in a van. I have heard though, both in Airstreams and in vans, stories of spray foam pushing out the frame in areas causing problems. A skilled installer may be able to clarify why this happens.
Airstream as well as Winnebago, have moved away from two-part spray foam due to problems.
Metal is your safest bet unless you are putting the plastic covers back on.
If you do put the plastic covers back on, caulk around the seams to prevent moisture from going into the walls.
If you want your interior walls to be another vapor barrier layer, the metal or plastic should be used and caulked airtight. The drawback is another step to being able to check on your wall.
If tin/aluminum tiles are used it’s best that behind them is airtight (though if you have enough insulation this might not be necessary). If you don’t have enough insulation, you could have condensation behind the wall cover.
Some folks are putting canned spray foam behind the tin tiles for an extra layer of air sealing.
I have also seen gaskets with solid silicone sheets used to make the walls airtight.
In a cargo van or trailer, instead of using metal walls, my preference would be to keep the walls as simple as possible so that you can open them up to check on problems.
You may want to use plastic sheets, or could simply tack up and cover the foam with the material of your choice:
There is no reason to use PVC, the most toxic plastic, in areas like the ceiling tiles. But real tin ceiling tiles could be used as a non-toxic alternative which also adds a fun look to your camper.
While The Vanual, a popular van conversion, looks very pretty with its wooden ceiling, I would avoid plywood as walls, ceiling or subflooring. There are just too many points where the wood hits the metal.
If you are intent on getting this look, you would have to have lots of insulation at all the metal ribs to make sure dewpoint would never be hit there.
If that is possible, then you could use plywood with strips of wood over it to get the look in The Vanual. Use a wood that can take high humidity.
I wouldn’t use wood to raise the floor joists as the wood right against the metal is usually a recipe for condensation and mold.
Rigid foam may be your best bet for floors to solve the thermal bridging there, with the same system of canned spray foam above and riveting used to make it 100% airtight.
Flooring materials that could be considered include:
Subfloor
If you are concerned about denting, use hard plastic sheets or metal. MgO board has worked for some but is prone to cracking (and is permeable).
Bed Platform – Non Breathable Set up
Camp Like a Girl and The Vanual used plywood for their bed bases. If it’s softwood plywood it needs a little time to offgas formaldehyde.
The other option is formaldehyde-free Purebond plywood (I wouldn’t use a non-moisture resistant wood species in a van or small trailer).
Purebond does come in moisture-resistant species, even cedar, but the glue is not made to withstand high humidity.
It also doesn’t let the mattress breath. Mattresses are very susceptible to becoming damp in campers. Even in a house, one should never put a regular breathable bed on a solid surface.
To prevent this moisture transfer there are two strategies to use on a platform.
One, cover the mattress with a waterproof protector before installing it in on the camper platform. This one is highly tolerable.
The other option is to use a bed that doesn’t transfer moisture and doesn’t mold, like this well-tolerated TPU air mattress (takes only a couple days to offgas to my standards).
An air mattress won’t keep you warm. I use the thickest Thermarest which is more comfortable than an air mattress for me (took a week or so to offgas enough for me) and I put a waterproof cover on it.
Bed Slats – Breathable Option
It would be best if the bed base was made of planks/slats that allowed some airflow. With this strategy, you may be able to use a bed that is not covered in plastic or isn’t an air mattress.
Either way, the bed should be flipped and checked often for dampness, especially if you cook or shower inside.
I would use bedding made of polyester, wool, or silk, (and not cotton) because these are more resistant to the high humidity in vans.
Since insulation is so tricky, many mold avoiders keep the van bare. The best way to stay warm is to have insulation below you and above you.
Extra protection from the elements would be to add a canopy over the bed and a heat source.
Insulate Under You
I like the method of adding insulation below you. There are a few ways.
A thick Thermarest like the Mondo King provides insulation under you.
But I like the idea of adding a layer of insulation below that. I like Thermacork, a pure cork insulation. You could use foam: EPS polystyrene (the kind made for packing or crafts should not have flame retardant), it is also a little bit breathable.
You then add your waterproof layer to your bed. (No air mattress in this setup). Then add a biomat or heating blanket.
Above you, you have your sleeping bag/blanket.
Ideally for warmth, if you can tolerate it, your heating blanket is actually inside the sleeping bag. Heating blankets can run off solar. The smaller ones are only 60 watts but will keep you really warm when inside a sleeping bag.
Stay Even Warmer by Creating a Canopy or Tent Inside
You can go one step further to stay warm and create a canopy or use a raised up tent inside the van. Anything to create a canopy – using the fabric of your choosing (as long as you have enough air) will keep this even warmer.
If the area inside my tent or canopy is large enough for this to be safe – I add a tiny heater. I use this tiny Honeywell heater in all my small structures. Be careful, you need to take a lot of precautions when adding a heater in a small space.
For cabinets, if you do use plywood, go for a formaldehyde-free plywood like Purebond (moisture resistant wood types only – the glues might not hold up to extreme humidity), offgassed APA exterior plywood, or use solid wood (which may warp in high humidity). I much prefer metal cabinets.
You need fans that move air out – one above the shower if you have one, and one in the general space.
My CampLite trailer had two fans and we still have problems just with cooking humidity making the mattress wet.
The standard camper fans are called Fan-tastic.
The Vanual has some cool tips for solar power, wiring, and appliances.
If you want to go off-grid you will need solar. And you generally you will need to tolerate a fuel stove.
The Vanual and other van owners speak highly of Goal Zero solar systems because of how easy it is to install. Some people just use the solar charger outdoors.
The other option is to wire the van to plug into a campground plug (or modify to plug into a house), this would allow you to cook on an electric hotplate and would allow an electric heater.
Right now I use an Instant Pot to cook everything and I release the steam outside. This is a really good way to reduce moisture in a van or little trailer. You can cook almost anything in that.
Using an electric blanket is a good heating option to save energy. The best kinds are the large ones with the 10 hour shut off time to keep you warm all night. If you don’t tolerate those, a biomat may be better tolerated.
I would not use the stand-alone propane heaters that go inside as they will not be safe for those with MCS.
For cooking, if you are off the grid you will need to burn some fuel to cook. Cooking outdoors is safer. Alcohol burning stoves are safer than propane. Though this won’t be tolerable for many.
For a fridge, I would go with a 3-way fridge that can run on propane solar or AC electricity. Unlike in most trailers, propane is stored inside in vans, so this could become a problem for some.
The Vanual recommends running this fridge on solar or the car battery.
Here is an example of a fully decked out custom van made for someone with MCS (you would want to see how the construction was done if you wanted to copy or buy this one).
Sensitive folks have reported liking the big 4: Nissan NV, Dodge Ram Promasters, Ford Transits, and Mercedes Sprinters.
Some have found that Chevy and GMC were not as good for people with chemical sensitivities.
Anyone sensitive should check out a number of brands. And of course, there are differences between the brands in terms of size and height and all kinds of things.
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Carl Grimes, Certified Indoor Environmental Consultant, reviewed the mold preventative insulation system for vans. Extreme mold avoiders are using this system with success.
I’m converting a small cargo trailer into a tiny trailer that can be used for sleeping and living. In the end, this model is only useful as a portable kitchen and bath. Other models are sturdier and may work better as insulated conversions.
The cargo trailer is a TNT brand DBL ‘A’ 6×12, White, 12″ extra height making it about 7 ft high on the inside. The extra height is well worth it I think for a sense of space.
Side and roof vent (side vents are so small that they bring in very little air. The roof vent can only be wide open if it’s not raining). RV door lock that locks from the inside (vital) and barn doors that lock from the outside (easier to handle than the ramp door). You may want to move the lock to the inside when living in it. Front and roof are curved in this one.
I recommend all of the products here, some products have affiliate programs and some do not. Upon purchase, I earn a small commission through affiliate links at no extra cost to you.
Costs in Canadian Dollars:
I have seen better prices in the US, you can go smaller and get a better price, but for me, 6×12 is the minimum amount of space needed to make a happy little home.
Joey was able to do this for $7000 with the factory doing most of the work. In the Facebook group Mold Avoiders on the Road, you can see people having smaller trailers renovated for under $4000.
Remove plywood.
Install window – 24 x 30 vinyl awning style to stay open even during the rain (you’re going to need air in such a small space). It’s vertical so that the framing did not need to be cut. I do not find the hard vinyl has a smell but you can use aluminum.
I wish I had put in two as it’s nice to have windows. One does bring in plenty of light through, along with the vent on the roof.
You can look for an RV window or you can use a tempered glass house window and reinforce the framing around it.
Install metal flooring 3/16 hot roll plate steel flooring, 1000 for the metal + welding. See this thread for an in-depth discussion on what type of metal to use.
Electrical work
A 30 amp panel with a campground plug and 4 outlets inside. You may be able to make do with fewer outlets but the electrician wanted a dedicated outlet for the fridge and one for the heater. Then I have one near the bed for a computer etc, and there is one up high to string up a light and run any kitchen appliances.
Have these renos done by the factory and not after you buy it. This was a huge mistake that costs me a lot of money and didn’t save me any time like I thought it would.
I should have known better as I had read Joey’s conversion story (highly recommend reading that for another version of a conversion and some ideas on what you might want to add. (I disagree that foam doesn’t provide a lot of protection from the cold and heat. 2 inches of XPS is R-10, that is really good).
How long it will take to customize one depends on the brand, the factory and the time of year. Add 2-3 weeks on to their estimate.
The back door in mine has structural plywood so that still has to be removed and needed metal reinforcements. The front end had plywood between the frame and the skin which was a major pain to remove. Look for a brand that does not have these two issues and you will save a lot of money.
If you want to do it yourself check out this thread (you have to sign up). Watching someone’s account of doing it herself is well worth it. You will see tips on taking out the plywood and choosing a metal for the floor.
Do the Walls Need Reinforcement?
A big question with cargo trailers is if you need wall reinforcement when you remove the plywood. There are two answers to this.
The first is that it depends on the brand, some brands will tell you that their trailer is good to go with no plywood, these have thicker frames like the steel CM trailers. Or some companies can customize it with thicker frames. See the pictures below.
The second answer is that the companies might say they are not strong enough but people leave it un-reinforced anyway. Erik Johnson, me and two other mold avoiders have taken out the plywood and not added anything that would replace it structurally.
Mine started leaking and the company that sold it to me claims that the reason it leaked is that the plywood was taken out and this means there is less stability and it’s easy for pieces to come apart and caulking to come loose. I have braced mine since.
If they won’t customize it without plywood, remove that part yourself and reinforce it (or don’t) yourself.
The first picture is a customized trailer reinforced with aluminum frames. Very robust. If you look closely you can see tape between the frame and the exterior, a mold risk.
The second picture is a CM all steel trailer with a robust steel frame, the frame is standard and the company does not recommend reinforcement.
The third picture is a standard frame, with plywood removed. Though it’s not reinforced the owner is doing just fine with moving it around frequently. The brand is Victory.
This picture is my trailer it has the least robust frame of the bunch, while the seller advised that it could be reinforced for longer trips (he told me this after the insulation was up). I have now braced/added strapping.
A cargo trailer smells much stronger than someone might anticipate a new metal box to smell. An extreme avoider in a hot climate would leave it sit for about a year before using.
I have seen two people who have turned around and sold them soon after buying due to the strong smell. Mine is now a year old and not totally offgassed.
The smell comes mostly from the body of the trailer. It is a glue smell and may also be oils on the metal. There are many other parts that are non-metal (differ slightly between brands) that may include:
Caulk of different types, double-sided tape (you do not want to buy a cargo trailer with tape in the frame – this is a mold risk), plastic on the back of the RV door, plastic and glue (very smelly) in the vents to the point that you will likely not be able to use these vents for air, rubber and foam (glued on) can be found around the RV door, around the barn doors, and possibly around the window on some models, there may be tape holding up wiring, there is the usual plastic coating on the wiring, plastic light and light switch may be included, there may be spray paint on wiring, there may be caps on bolts, screen on top vent, there is also exterior paint which some people have said they are offgassing but I could not pick up a smell on.
In such a small space there are also the tires on the outside to consider – on a hot day you will smell these.
Rustproofing chemicals may also be added to the frame. (Thanks to Madonna Ramp for some of these materials from other brands).
A lot of this can be covered and you can see in mine that it is almost completely sealed up. If you buy one and it smells strong, give it time and/or seal it up like I did mine.
Every trailer takes time to offgas. Someone was able to get the company Mirage to build without glue or caulk, but she was not able to tolerate the trailer brand new. I would not recommend leaving out glue and caulk.
Buying a Used Cargo Trailer:
I did not see any used cargo trailers in my area when I was looking but you can sometimes find these. You would want to know what it was used for. Look for gunk and rust that will accumulate at the bottom around the frame.
Building out the Interior – How Mine was Done (The Second Time)
There is a rumor that spray foam will crumble with movement in a trailer but speaking with the company Great Stuff and some folks who have taken apart trailers they have not seen this be a problem.
EMFs:
All this metal and foil did not stop wifi or cell phone reception – it lowered my wifi connection only slightly. If you are concerned about EMFs consult with an EMF specialist and test out a metal structure before buying. In theory, it is a Faraday Cage that blocks out some external sources of EMFs and may intensify what is on the inside.
Fixing the leaks
My TNT Mirage Trailer has a number of poorly built aspects. The company took no responsibility for this and the leaks.
What has to be fixed on this model or checked on any model: The back doors were leaking, the top sil needed caulking, the door seals were not done right, the doors were bulging at points, bending the doors and adding gaps for leaks. The front diamond plate had nothing behind it, it was a negative lap – a poor design, the front wall should come all the way down. The front plastic cap on the top roof is also a negative lap.
Vertical seams have the ability to let in water in a big storm or when driving it in the rain. Always check windows, doors, and any openings. Screws should be caulked as well. Look for a well-done roof design. This roof design is good. I have seen custom designs with vulnerable roof seams.
Aggressively hose test this before adding insulation and know where the weak points are. After moving it is when things are most likely to come open.
When recaulking metal parts, attempt to open things up and get caulking between parts and not just over the seams.
These trailers are difficult and I would not attempt insulation in this style/brand again.
Erik Johnson’s Cargo Trailer (MECU):
Erik is the pioneer of cargo trailer living. He called his trailer and camper MECUs (Mobile Environmental Containment Unit). Erik used EPS foam without flame retardants. I don’t know how he sourced this but I would think this is the kind used for packing, not insulation.
In Erik’s trailer, he left a gap (like I did at first) between the foam and the exterior. He put in weep holes at the bottom in case condensation did find its way to the back. Some trailers like mine come with weep holes.
He has said that there has not been any condensation at the back and he has had this for more than a decade. I put the insulation in front of the frame which created a space naturally behind it (though my floors and ceiling have no space).
This method did not work for me, major condensation formed behind the walls and I don’t know anyone that was able to get this to work.
Here is a video of his camper which is done like his cargo.
Other Trailer Options:
You can build out the interior as much or as little as you like.
Finishing the Interior:
For now I’m using these mats on the floor temporarily. They smell like straw.
I am currently offgassing Marmoleum (takes one month in sun to offgas) but I don’t like that there’s a jute backing under the Marmoleum against the metal, that’s a mold risk).
I had considered Cali Bamboo Cork (not sure yet how long it takes to offgas, definitely much longer than Marmoleum).
Note: Flooring I ruled out: Thermacork decorative cork the only cork I know of that is heat-pressed with nothing added – not good for floors. It flakes easily and won’t last long.
Cork underlayment – I bought this and tested another one that claimed 0 VOC. It is going to need a lot of time to offgas despite these “0 VOC” polyurethane glues (not at all). A year later I have not offgassed the cork floorings (though they were not out in the sun for a year).
If you have space, I like this organizer.
Heating, Cooling, Lighting, Laundry:
Kitchen:
In a high humidity situation like a trailer, tent or other camping structure it’s important to have a bed and bedding that will not go moldy.
My bed will be up on slats soon (right now I am turning the Thermarest over every few days – it went moldy so it is crucial to get it off the ground onto slats).
Cotton does not hold up well in high humidity, so I have used more mold-resistant materials.
I am available for consulting to help customize a little “safe room” cargo trailer or custom made trailer. I can help with everything from choosing materials to managing the whole build.
I also help you to decide between different housing options, from building a conventional house, tiny house, trailer to setting up tent camping.
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