Cargo Trailer Conversion

Converting a Cargo Trailer into a Travel Trailer

Part 1: Getting it up and Running
My current project
I'm converting a small cargo trailer into a tiny trailer that can be used for sleeping and living.

The cargo trailer is a TNT brand DBL 'A' 6x12, 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.

Costs in Canadian Dollars:

$6100 cost of trailer
$3600 cost of renos at trailer shop - metal floors, install window, take out plywood (much cheaper, and probably faster if you have the factory do these.)
$1500 cost of insulation
Labour for insulation and vapour barrier, foil and glue - lost track
$1300 Electrical (+ $185 for CSA inspection and approval - allowing me to legally park the trailer in Canada)

I have seen better prices in the US, you can go smaller and get a better price, but for me 6x12 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

Necessary Renovations:
Dreaded plywood
between frame and
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 though, 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 - 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 computer etc, and there is one up high to string up a light and run any kitchen appliances.

My electrical
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 customise one depends on the brand, the factory and the time of year. Add 2-3 weeks onto their estimate.

The back door in mine has structural plywood so that still has to be removed and metal welded to it to hold it together - this is still going to cost a lot. 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 customise it with thicker frames. See 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 mould avoiders have taken out the plywood and not added anything that would replace it structurally. So far so good. I'm not sure if I recommend that, but we have all moved ours around and been fine.

If you want to play it safe go by the recommendations the company suggest to reinforce it. If they won't customise it without plywood, remove that part yourself and reinforce it (or don't) yourself.

The first picture is a customised trailer reinforced with aluminum frames. Very robust. If you look closely you can see tape between the frame and the exterior, a mould 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), so far it's doing fine on the highway. I don't feel really confident yet about long trips.

Toxicity of a New Cargo Trailer:

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.

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 mould 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 is Done:
XPS with Great Stuff
  • XPS Owens Corning Foam 2 inches on walls and floor (you can also use polyiso, the most well tolerated foam, or EPS which is not a vapour barrier on its own but is usually faced with foil or plastic). 2 inches XPS is R-10. If you are going to a climate that is extremely cold, add another layer of foam - polyiso or XPS on the inside until you get a high enough R-value for your climate. The reason I chose XPS is that is has a high R-value and it doesn't lose its R-value in very cold weather like polyiso does. I also could not find polyiso in my town. 
  • 1 inch Foil backed EPS on ceiling (because I needed something thin enough and flexible enough to be curved on the ceiling) (Note: This is backwards, there should be more insulation on the roof but I wanted the roof to stay curved and the insulation to stay between the frame so I kept it simple.). The brand was R-Tech but I can't find a link for this. I can add another layer of 1-inch foam if it gets too cold.
  • Great Stuff spray foam on the gaps of the rigid foam (airtight so no moisture gets behind the foam). There is one for small gaps and one for larger gaps you will need some of each.
  • Heavy Duty aluminum foil glued up to seal in the smells of the spray foam and the trailer body in general. Double layer over critical areas (gaps, seams, anything that smells). You may want to try one layer and go up to 3 layers if needed. Check around crucial gaps and tricky areas giving those more attention to fully seal in the smell. I would say the smell is 99% gone/virtually odourless. 
  • A Fantastic Fan in the roof vent would be helpful for ventilation, drawing air out of the top will draw it in the window and turn over a lot of air. The fans also help with humidity. This has to be wired in with the electrical.
How we Installed it:
First layer of foil on seams
The foam is not being held in place by anything other than the power of it being held between the floor and ceiling. You can use some tape or glue if necessary. The canned spray foam is filling in the gaps (leave that to cure for at least 24 hours). Over the seams we put heavy duty aluminum foil, sealing with glue. Then overlapping over those edges is another layer of heavy duty foil.

We used natural glue to attach the foil - this Gum Arabic with water - almost no smell to that, very light and natural. This can be used to seal up conventional trailers as well. Others have used it to seal a room in a regular house. This is a very sticky glue that can adhere to metal, foam and I would assume a large number of materials. It can be tried anywhere where an internal vapour barrier is not a problem. It can be removed with a steamer, but it's not easy. I'm not feeling 100% confident on using this glue since it cannot dry between foil and foam.

There is a rumour 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.

I'm not putting walls up in this one. You could put up metal, plywood, or plastic, but I want to keep this really simple.

In an ideal world you have 2 competent people working on this full time you could get it done in 4 or 5 days. Add extra time for real world problems.

Here is a video of where the trailer is now (in progress) - hard to show in photos:


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.

My First Attempt and What Went Wrong:

My first attempt totally failed. I tried to buy a cargo off the lot and sleep in it within three days. We put up XPS over the plywood (sealing it in in a dangerous double barrier system), we used tuck tape to tape up the foam. This absolutely reeked. Then we covered the entire interior with mylar blankets and taped that up with aluminum foil tape - that absolutely reeked as well. So from there we took everything down and did the renovations properly (which means taking out plywood and putting in metal floors and a window). I found out taping up seams was not going to work. Even the most tolerable foil tape in a small enclosed space becomes overwhelming (I am very sensitive but not by any means among the most sensitive).

Erik Johnson's Cargo Trailer (MECU):

Erik's story
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) between the foam and the exterior. He put in weep holes at the bottom in case condensation did find its way to the back. 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).

He has an interesting (non-toxic) method of putting up the foam: Erik says: "I riveted small strips of aluminum to the steel wall studs that are four inches long. For two sheets of two-inch styrofoam. Put the styro in place and riveted one-inch aluminum angle to the four-inch strip, using the "L" of the angle to secure the styrofoam. This vertical angle then gave me a place on the wall to attach shelves." This eliminates the need for spray foam, caulking or tape to seal up or hold up the foam, it also means it's not air tight. This has not been a problem for Erik. Though I was worried in my set up about it not being a perfect vapour barrier.  Erik used wooden floors and not metal.

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.
  • You could add batteries but consider how long these will last you away from plug-in power.
  • You could add solar panels but this doesn't get you a lot of power, it may be easier to just buy a solar kit that is portable that is made for camping.
  • If showering in another building, campsite bathroom, or outdoor shower is not an option for you, you could install basic plumbing. You would want to avoid tanks and have very simple plumbing that goes directly out to a bucket or pipes out into a grey water system. You will have to make sure you are following the rules with grey water here. I want to avoid all cooking, showering, and clothes drying inside to keep humidity down.
  • Options for outdoor showers include simple bucket showers, passive solar shower (that one is PVC-free, unlike most of them), active portable hot water shower (this one comes recommended by mould avoiders), or an outdoor tub big enough to bathe in. A privacy tent can be used to shower outside or set up a toilet outside. You can also DIY and set up something simple like wrap house wrap around 3 trees, or tie string around 3 trees and the string holds up shower curtains.

Finishing the Interior:
    WALLS: I was going to tack up these posters and some regular wallpaper - Farrow and Ball is a well tolerated non-toxic wallpaper. It is way too humid in here to put wallpaper though. I think that is unlikely to work in most climates. I am not eager to cover my walls with metal panels or plywood because I want everything to be simple and easily accessible. Other options for the wall: the grey side of housewrap, paint the foil with AFM metal paint (if you can get the foil very smooth and without glue everywhere), these polyethylene wall tiles (if you can tolerate the glue), seal everything with shellac and then paint over, or, other plastics made for RV/vans tacked or taped up. I will be using plastic RV panels.

Marmoleum from

FLOORS: 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 for me) and 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).


    BED: I'm going to customise a locally made solid wood bed with storage underneath - the bed will be up about 2 feet and take up more than half the length of the trailer, creating a large storage space underneath. I would like it to be made partially of Purebond plywood but even that needs to offgas, so I am planning a solid wood bed instead. Cedar is the best bet for holding up to high humidity environments and not going mouldy, but pine should work as well. I will seal it with shellac to seal in as much of the wood smell as possible. (I will do a post just on shellac.) A metal bed frame would be a safer option.

Heating, Cooling, Lighting, Laundry:

  • I’m hanging up this light bulb (the cord smells strong and offgassed in my car for a while). I also like this little nightlight but it won't provide much light.
  • In the summer I will use a portable AC, I like this one for the level of offgassing. I throw them away every fall as they tend to go mouldy after one season or two and I have nowhere to store them. 
  • I’m using this to dry my clothes and I love it. I don't want to add humidity in the trailer so I am using it outside under cover. It works well even in humid and cold outdoor temperatures (and it's not as mini as it looks). 


  • I bought this fridge which needed a lot of offgassing outside including running it outside. This one smelled more than other brands I have tried like Danby. I like Walmart for fridges as well. 
  • I'm using this kitchen island which offgassed fairly quickly but you could use a metal version if you want to avoid wood (and wood sealers and glue). 
  • I offgasesd this cutting board pretty fast. I'm just posting that because I love it so much
  • Thrift shop bowls 
  • I’m using a pressure cooker to cook - you can make almost anything in this. If you use it outside or at least release the steam outside you will have very little or no added moisture to the trailer. You can get away with no other stove, oven or microwave. You just need an extension cord to use it outside.
  • I’m going to buy the travel Berkey for drinking water, there is no plumbing in the trailer. Berkey is ideal for well water and water from campsites if you are not buying water. 

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 mouldy. My bed will be up on slats soon (right now I am turning the Thermarest over every few days - it went mouldy 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 mould resistant materials.


I am available for consulting to help customise 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. Here is my consulting page.

Part 2 will show the finished product with all the interior design and furniture


Making purchases through affiliate links helps support me and this blog. Amazon and Walmart are affiliates.

The Best Air Purifiers for Mould - A Review of PCO Machines

PCO Air Purifiers - Which One I Use and Which Ones are a Scam

PCO (photocatalytic oxidation) is a technology that breaks down mould, VOCs as well as some pathogens. My interest in these air purifiers comes from first-hand accounts of this helping people with mould and VOCs and from the studies showing the eradication of mould and mycotoxins.

Image from
This is a technology that is extremely promising for those sensitive to mould and it's important that we test this out as much as we can. There has been so much talk about HiTech (both good and bad, which claims to be PCO) but very little talk about the more recognised and more affordable brands - I'm really urging the mould community to gather more data on this by trying some of these other models.

I am really excited about this technology as something that can safely break down mycotoxins and odours. Some people may be interested in its effects of breaking down viruses and bacteria as well.

A very brief explanation of PCO is that UV light hits a catalyst, usually titanium dioxide, creating hydroxyl radicals (OH). These OH molecules bind with and break apart pollutants into harmless molecules.

What I'm Using

I use the Vornado air purifier. The Vornado PCO300 ($260) and PCO500 ($470) are the air purifiers with a great value. It is a PCO air purifier plus it has true HEPA and activated carbon. Most PCO units are much pricier or don’t include all three air purification methods.

True HEPA and activated carbon capture dust, pollen, pet dander, smoke, bacteria, mould spores, dust mites and odours including VOCs. PCO and carbon are the main technologies used to reduce odours and VOCs. (Ozone can as well, but it is very risky, I have a post all about ozone). PCO actually breaks down molecules including moulds. I like that it has all three main air purification methods.

Why I chose this machine:
-The PCO component has true UV and titanium dioxide
-Respected brand
-Noticeably brings down odours in new apartment and new cargo trailer
-Has a 5-year warranty
-Replacement parts are reasonably priced ($25 bulb every year, $35 titanium dioxide screen every 5 years - for the PCO related parts)
-Does not put out ozone

What I don't like about it is that the unit itself offgasses, though not everyone thinks so. After two weeks I found it to be good.

The difference between the two sizes is that the 500 has a lower low speed and a higher high speed. The 500 has 2x the HEPA and activated carbon of the 300. They both have the same PCO technology - so if you want to increase the effectiveness of the OH molecules in a large space you would want two of the 300 instead of one 500. The 500 moves 184 CFM and is advertised for 265 sq ft - around 5 air exchanges per hour.

Some other PCO units are more or less the same unit re-branded: Continental Fan CX1000, Catalytic Pure Air, Field Control Trio / Sun Pure SP-20C. They seem to use a very similar PCO catalyst style to the Vornado with a titanium dioxide plated metal screen.

Another brand that is very affordable that also incorporates HEPA, carbon and PCO is GermGaurdian. I have heard of people using it in trailers and being happy with. At $89 it's a steal. And it has 5.5 ACH in 171 sq ft.

I will review a few other brands that I ruled out for myself: Air Oasis and HiTech, as well as Airocide and Molekule.

Air Oasis

The Air Oasis 3000G3 model ($500) is rated for 3,000 sq ft and only moves 11 CFM of air.  3,000 sq ft at 11 CFM is 0.02 air exchanges an hour. That is very little air movement.

Note on air exchanges per hour (ACH) - this is a key area of comparison with air purifiers  ASHRAE (The American Society of Heating, Refrigerating and Air-Conditioning Engineers) recommends a minimum of 4 ACH for patient rooms in hospitals, 5 for intensive care units and 25 for operating rooms. For the purposes of those extremely sensitive to mould and VOCs we want about 5-10 air exchanges per hour. This Air Oasis has 0.02 air exchanges per hour. (I am using 8 ft ceilings in my calculations of CFM to ACH.)

Air Oasis does more than just PCO it also, as the company states, “creates ionized hydro peroxides”  (AKA it's an ionizer) which puts out ozone and does NOT meet the California regulations on a safe level of ozone (CARB). You can have one made without the ozone production component.

It has a 3-year warranty and the replacement parts are $80 every 2 years.

I know this brand because it is being promoted by top doctors. I was surprised when I dug into it to see how ineffective it would be at moving air, and that it gives off unsafe levels of ozone (as determined by CARB). There is more of a discussion of this brand and their technology in the comments as this machine claims to be doing something different than just PCO or just ozone machine.

HiTech Air Solutions

The inside of the 110 model $5995
HiTech Air Solutions, a brand known among extreme mould avoiders, makes Air Reactors that claims to be PCO machines. To start, the 101 model ($2000) is very expensive relative to the other PCO machines. From looking at the inside of the machine they use basic components that total under $150 for all visible parts: four foam/coarse dust filters, two UVC lights, two computer fans, and a 4U 19" rack case. The claim here is that some of these filters are photocatalysts that produce OH molecules - that there is something invisible called "Technosite®"  (no evidence of this trademark with USPTO) impregnated onto the filters. They may be using something similar to PALCCOAT (confirmed not partnering with this brand) which is a clear titanium dioxide catalyst (FYI $13 per square meter). I have found no evidence of a patent held by HiTech or Ray Robison (owner) on anything in the machine.

(I have also seen two other odd claims from sales reps of the company - one, that the filters are coated with Sporax and that both the filters and the bulbs are also coated with something proprietary - both things that I would want to know are safe to use with UVC light).

HiTech claims to be doing something different than the others. They claim their OH molecules (which are produced by the PCO process) last much longer in the air than the other air purifiers' OH molecules (~6 weeks instead of ~15 seconds) based on "a study by Texas Tech", though this study cannot be produced by the company. Dozens of phone calls were made to track down the existence of this study and nothing turned up. Even more, the University claims it does not conduct studies give the results on the phone and then withhold the report for large sums of money (as the reps claim). I have not found any evidence that this produces a totally different kind of OH molecule.

I would like the company to disclose what they are using in this machine so we can know if it is safe and effective, or, provide the studies that show which molecules and byproducts this machine produces. The burning smell is worrisome to me. The accounts I have seen of bad reactions are also worrisome.

HiTech claims it produces 99.9% pure air. I have seen no studies to back up this very broad claim. What is the level of contamination in the air to start, and what is "pure air"? Also note, PCO technology does not filter particulate pollutants (EPA).

I have contacted a technical rep, sales rep and the owner for these studies - they responded but were not able to provide them. Others interested in this company have contacted them as well for this information.

The HiTech 101 is 142 CFM and claims it can be used in 1600 sq ft which is only 0.7 air exchanges per hour. Their bigger units are ~$5000 and ~$6000 dollars. The HiTech sales reps make 25% commission off each unit and they usually recommend multiple units for houses. The commission for the three sizes is roughly: $500, $1000 and $1500. The cost of the replacement parts are $140, $190 and $295 per year, for the three different sized units.

HiTech has not submitted their Air Reactors to CARB to confirm they give off a safe level of ozone. However, the bulbs they are using are USHIO brand UV bulbs with a 2G11 / PL-L base which do not give off ozone. They use another brand as well, LSE Lighting UV bulbs, with the same base. From what I can tell this bulb would not be any different from the USHIO brand.

I’m calling on HiTech reps, especially doctors to consider the following:

-We don’t know what is in the machine - it is invisible, not disclosed, and the company has not backed up the claims of which molecules and byproducts this machine produces
-The company has made numerous unsubstantiated statements - there is no evidence of any university studies, no evidence of FDA approval, no evidence of a patent, no evidence of a trademark (on Technosite)
-I have seen people have bad reactions - it is not proven to be safe
-This machine is an unnecessary financial burden on patients when there are well-established brands selling verifiable PCO machines on the market for a fraction of the cost
-Making $1000+ off each (medium sized) unit is certainly a nice incentive for sales reps, though ethical concerns must take priority

FDA Approval

The FDA approvals I have found are one for a PCO machine involving titanium dioxide (it proved to destroy some bacteria, viruses and mould) for specific commercial uses. The Airocide also has FDA approval. HiTech claims to be FDA approved, I can find no evidence of that. Anyone can search for FDA approvals here.

HiTech did respond to this article, some of the statements have changed from what I have records of and the updates are in the comments.

Other Popular Brands

Other popular PCO machines are Airocide (CFM 14 “Cleans any size room” which I suppose is technically true, but is not going to get you 5-10 air exchanges in most rooms, $600.) This doesn’t move a lot of air, but I like that the website has studies confirming that it doesn’t give off ozone and a short study on breaking down mycotoxins. It looks cool which is a major plus. The claims about removing dust, dust mites and allergens are not all that accurate. PCO machines do not filter particulate pollutants (EPA). It has a 5-year warranty and 60-day money back guarantee which I like. The main drawback here is how little air it moves.
Molekule (CFM 80, 1 air exchange per hour in 600 sq ft, $800) is a slightly different technology called PECO. Here is a summary of their studies - very promising results on eradicating mould. It is very beautifully designed. This company has well respected big names behind the design. The inventor of Molekule is the person who discovered PCO. He has an impressive resume. I would love to try this machine out as I think it is very promising. They are still a new company (started 2016) so I would be worried about the possibility that they won't be around to provide replacement parts. However, I do have a certain amount of faith in this company based on the founders. If it proves to really work well, or better than PCO, then they will do well (their power point they showed me showed it worked better than PCO). The warranty is only 1 year, which is short compared to the others. If you can afford it, and design is important to you, I would consider this machine. Here is a coupon for $75 off.

Both of these require $100 a year in replacement parts.

Most of the PCO machines do not include HEPA and activated carbon like the Vornado, they are more expensive, they don't move as much air, and their replacement parts are more expensive. (Airocide used to have a unit that included HEPA for $800, which is not available right now.)

Adverse Reactions

I have heard of people having bad reactions to HiTech. I have heard only one bad reaction to Airocide, and a couple bad reactions to AirOasis. I do not know what accounts for these bad reactions. It does not appear that there is an ozone issue (apart from AirOasis). I don't have enough data on all these machines to know if bad reactions are more prevalent with any particular brand.

HiTech reps speculate to buyers that the bad reactions may be helpful (some kind of detox or herx) which is ethically unsound in my opinion. With no data to suggest this is detox, we should take a precautionary approach.

I would love to hear from more people who have tried these other brands. Let me know if you have had good results or a bad reaction to a PCO machine (other than to the plastic or glue of the unit).

Since writing I have heard one bad reaction to Molekule and one to Germ Guardian.

It is possible that PCO is creating harmful byproducts in high VOC buildings.

The Burning Smell

According to Airocide the UV bulbs themselves emit a bit of a burning smell at first. They burn theirs in for two days, but sensitive people can smell it for up to a week. The Vornado PCO had a very slight burnt smell at first which seemed like the smell of carbon. HiTech states that the burning smell is mould/mycotoxins breaking down. I see no evidence for this claim. Airocide made a statement that mould does not produce a smell when broken down by OH molecules.

A HiTech user also stated that the UV lights have burnt right through the "reactor pads". This is consistent with a theory that the UVC lights are burning the "reactor pads" and causing a smell.


My recommendation is based on the most affordable and effective product that I have found. Buying your products through these links helps support me and this blog.

This post is not sponsored by Vornado. The Amazon links are Amazon Associate links. The Molekule discount link does provide me the ability to earn points towards buying one and I would really like to try this machine.
This post was written with the technical assistance of an engineer, though the opinions and conclusions are my own.

This post was written June 2017. I do my best to keep all my posts updated if there is new information.

Zero VOC Flooring

This post is organised into three categories, those that are the most tolerable, those that would be OK for most sensitive people, and those that might work for those who are not extremely sensitive. 

1. The Most Tolerable


Wood flooring will always be my number one choice. However,  wood (and many natural aromatic oils) contain terpenes which are problematic for many people.! For those sensitive to the smell of wood this is not a good option. Aromatic woods like pine have much higher VOCs than oak for example. Wood also has a higher possibility of harbouring mould than less porous materials. To prevent mould you should make sure your wood has been kiln-dried and kept dry until you have a roof on it. Wood may also contain anti-sapstain chemicals which could explain why some people react to wood used in building and not wood in the forest. 

There are plenty of acceptable options for finishing wood. I used Hemp Oil on my floors. AFM is another great non-toxic finish. More about wood sealers in my post on sealers.

Most people should be fine with softwood plywood which rapidly offgasses. For subfloor adhesive AFM Almighty Adhesive is super tolerable. Another option is Liquid Nails Subfloor Adhesive it is less than 20g/l (lower than AFM Almighty Adhesive, but I find AFM more tolerable).

Polished Concrete

If polished concrete flooring makes you think IKEA warehouse, think again, polished concrete can look beautiful.

The Retroplate system is completely non-toxic/VOC-free but is not as cheap as I had hoped. It is available across Canada and the US, you just have to find someone who specializes in that system.

You can do acid stains, add natural pigments, use white cement, or add white sand to Portland Cement to get the look in this gorgeous photo.


Glass tiles are inert and super-MCS friendly.

Marble is good in theory but most of it has a resin put on it at the factory to fill in tiny holes and fissures, and it might have a (chemical) sealant on it as well. Though a pure slab, or tile, can be sealed with Tung Oil. (Tung oil has a smell and might not be tolerable) or AFM Mexeseal.

Slate is also good in theory, as long as it doesn't have a chemical sealer on it. Seal with 
AFM Mexeseal.

Concrete tiles are my preference because of the beautiful designs. Look for Eco tiles or ask what additives are in the concrete. I sealed mine with AFM Safecoat Penetrating Water Stop.

Porcelain and ceramic are safe if lead-free and do not contain radioactive substances.

Imported glazed tiles should be tested for lead and radioactivity. A client just tested American made tiles that stated they were lead-free, but when tested they showed high levels of lead. So it might be wise to test any glazed tile regardless of origin. And be extra careful when removing them as the lead dust is particularly harmful. Tile over if possible instead of removing.

Wood look tiles claim to be 0 VOC even though there is a printed image on them. The glaze seems to block this. I have tested them and they do not smell any different than other tiles.

Air Cleaning Flooring

Crossville Tiles have a coating option called Hydrotect. This uses the PCO process to clean the air. A layer of non-toxic titanium dioxide is used to coat the tiles. This reacts with UV light, and just like the PCO air purifiers I reviewed, creates a reaction that can break down some bacteria, moulds, VOCs and viruses.

I don't know how impactful this tile coating that uses natural UV light will be to the overall air quality in a room. The company does have some reports that show reduction in bacteria, which may be worth while to some folks.

If you read my article on PCO air filters you will remember that some people have a bad reaction to this process. It's possible that in a high VOC area it creates formaldehyde. I would try out a PCO air purifier before installing this tile to make sure it works well for you.

This technology is also used on wood floors.

Natural Carpet 

For natural, non-toxic carpet look for chemical-free fibers (normally wool), no flame retardants, no mothproofing, no stain repellant, natural padding and either no adhesive or a non-toxic adhesive. I have reservations about natural latex and would not use that product in my house because of how mould-prone it is.

Nature's Carpet is made with wool, no mothproofing, natural latex, natural dyes and a non-toxic padding. Either tack down the carpet or use a non-toxic glue. 

Other good companies are Earthweave (wool - contains natural latex), Natural Home Products (wool) and Hibernia. I have sniffed Hibernia and it does have a wooly smell (as you would expect) but not a chemical smell in my opinion. 

If you have conventional carpet in your house seal in the VOCs with Carpet Seal.

Commercial grade carpet is a lot harder to find in low VOC. I have reviewed and sniffed a few of the ones that claim the lowest VOC levels. I could not find any that were 0 VOC.

Flor: Most of their carpets are commercial grade. They claim they have the lowest VOC levels in the industry as of 2017 though when probed for information on their VOC levels or any evidence to substantiate that claim they did not have any. They have Green Lable Plus which you can find almost anywhere now and is in no way a low level of VOC. However, when testing their carpet it did not have that tell-tale new carpet smell. The initial smell was as strong as other regular brands but it seemed less offensive (I know everyone is different here though.) But what did impress me was that the sample offgassed way faster than other brands that have the tell-tale new carpet smell.  A few weeks outside and it is fairly tolerable for a conventional carpet. 

The other good option for commercial grade is wool. Though companies are more reluctant to use wool because it is more expensive. The Godfrey Hirst wool commercial carpets can show test results of very low VOC levels. Though they do have that classic carpet smell still. 

Woolshire wool is also rated for commercial, I found it much more tolerable than Godfrey, it smells wooly but not like chemicals that I can pick up. It does have moth proofing in it. It smells similar to Hibernia brand. 

So if I was picking a commercial brand I would consider Woolshire first and then Flor. 

2. Good for Most Sensitive People

Pre-finished Hardwood - Usually finished with aluminum-oxide-infused polyurethane and cured under UV lights, these are usually very well tolerated once cured. I consider this to be safe product for the chemically sensitive. Test it first. 

Terrazzo - Terrazzo is a little complex as there are different materials, resins and sealers involved. But there are systems that are 0 VOC and low VOC. 

Natural linoleum - Marmoleum is made from linseed, rosin binders, wood flour, limestone and dry pigments which are mixed and then calendared onto a natural jute backing. It's got a UV cured sealer on top and this is the glue used to install it. I found that after one month the smell all but disappeared from the product. I am using this in my trailer. I was surprised and impressed since I don't normally do well with linseed.

Fiberglass Floors - Tarkett FiberFloor is a flooring made of fiberglass, foam and coatings. It may have a mildewcide in it. It is extremely low-VOC at 10μg/m3. This would be tolerable for most people. 

3. May Work for Those Less Sensitive 

Engineered Woods - Junkers, Kahrs, and Wood Flooring International all meet EU emission standards. The substrates can still be problematic. There are some engineered woods that are formaldehyde free (Kahrs) or use only phenol formaldehyde which offgasses quickly (Cali Bamboo). 

Cork, like wood, has a natural odour (terpenes). A resin is used to bind all the small pieces of cork together into flat pieces (I have seen polyurethane binders). In theory, you can make tiles or rolls without resin (they heat press them) but this is not how cork flooring is made. An adhesive is required either to glue it down (and there are 0 VOC glues for this) or in the floating floors it is usually glued to a fiberboard or substrate which tends to be problematic. It is finished with urethanes/acrylic which may be tolerable once cured. I have tested Cali Bamboo cork which I found to be the best one. US Floors was the second best. NOVA and Cancork smelled very strong to me. 

Bamboo requires resin or adhesives and a finish. However, there are many that are GreenGuard certified for low emissions. This wood is problematic and is known to shrink. I put it in the same category as laminate and engineered. Not good usually good enough for the chemically sensitive. 

Laminate does give off chemicals, but there are some low-VOC options. You might want to check out the brands that have GreenGuard certification. It doesn't require adhesive which is a bonus. Generally this is not low-VOC enough for a healthy home. I have seen better options in the engineered category. 

Hard Vinyl - the kind usually seen in schools and commercial buildings tends to be well tolerated. It would be an unusual choice for a home. 

4, Toxic! soft vinyl, conventional carpet and conventional linoleum all give off major VOCs.

Disclosure: Some of the links to products and supplies on this page go through my affiliate partners. This post uses Amazon Affiliate links. Whether a product has an affiliate program or not does not influence my choice of recommendations. Buying through these links helps support this blog and does not affect the price for the consumer. 

Building a Mould-Free Tiny House

Building a Mould-Free Tiny House 

This article will discuss preventing mould in tiny homes that are custom built. Usually on wheels, but much of this could apply to lane houses and other tiny homes not on wheels (though I don't discuss foundations here). This will apply to some prefab but not all types.

Major problems with tiny houses that cause mould:
Re-doing my insulation
  • Very few people hire an architect, engineer or other building science expert to design the system.
  • Many tiny home companies are new and the builders lack experience or are not experienced enough in all aspects of building (from plumbing to roofing, to installing heat pumps, to insulation, and moisture management).
  • The DIY movement is a problem because the size of the home makes it seem like you can do it yourself, yet you still need all the knowledge of all the  contractors: electricians, plumbers, roofers, architects etc. to build a house. The size of it does not necessarily make it simple!
  • DIYers ofter learn from other DIYers via the internet, copying others' mistakes.
  • The movement is new and it can take 10 years for some mould problems to show up.
  • Most tiny homes do not need to follow building codes. Almost anything goes in most places, resulting in poor building practices.
  • Homes are built in one climate and shipped around the US and Canada to other climate zones where the moisture management system may not fulfil its function. Owners may also move the house to a different climate zone. 
  • Only one year warranty on many houses will not be long enough to cover mould issues. 
  • Many tiny homes I have seen have simply invented wall systems that would never be used in a regular house. 
  • I have seen major problems with the moisture management systems such as vapour barrier errors, and smaller but still problematic practices like lofts built with mattresses right on the floor with no ventilation, and inadequate exhaust fans.
  • Lack of attention to detail that comes from inexperienced builders or those not concerned about mould.
  • Building by prioritising non-toxic materials over building the correct moisture management system (because you remove or replace a part of the system with something non-traditional).

Water on ceiling due to improper vapour barrier
When I first set out to build my tiny house I was mostly concerned with choosing healthy materials that were 0-VOC. It was only after I took the house apart (almost completely) to fix the problems my builder made, that I realised the extent of knowledge needed to build a mould-free home. I thought you just leave the construction details up to the contractor, but my builder made almost every mistake in the book.

From interviewing and working with dozens of contractors in my area, I have found one out of a few dozen who was knowledgeable and detailed enough to renovate the house in the correct way.

The two most important aspects of designing a mould-free tiny house are:
  1. Have an architect (or other building science expert) who specialises in mould prevention design the moisture management system. This is everything from the wall system to the roof, the floor, and the ventilation. They will also need to take into consideration which materials you can and can’t use to design the system. Take the time to do this in detail before you hire your tiny home builder. I can also help with consulting on materials at this stage because the architect needs to know which materials can and cannot be used/tolerated.
  2. Extremely detailed supervision. I have fixed everything from my bathroom fan to my walls and roof. Taking my attention away from the project for more than an hour led to mistakes by the contractors who simply do not care about mould prevention. Even if you find a good owner, that person leaves the work to his labourers or subcontractors who are not well supervised. Here you can either hire someone extremely competent to supervise, or you can supervise yourself. If you supervise yourself, take the guidance from your architect, and learn the basics in order to follow those guidelines (or you will be calling him or her every few hours). Make sure the builders have a very detailed plan of how you want things done so that when you come into supervise you are staying on plan. There may be a clash of egos here, but you need your house done right and most contractors do not have the right skills. 
Of course choosing the right expert to guide you is also important, so before you do that you should be aware of a few different ways to manage mould that are popular and get a few opinions before you decide on hiring someone.

Here are a few different systems:
  • Passive house design - Passive house design is a very detailed system that uses a lot of calculations to manage the moisture in a scientific way. You can check out 475 to learn more about this. 
  • Breathing walls - Check out George Swanson who uses breathing walls and look up the science behind not using vapour barriers. 
  • Walls with vapour barriers - Learn the basics on vapour barriers and what smart vapour barrier are. 
  • Wood frame houses versus metal framed houses.
  • Building with SIPs.
Here are a few terms and ideas to learn about so you can follow along with your expert:
  • Flashing of windows and doors - the instructions on this are fairly simple and yet they are often not followed precisely (they need to be!) 
  • Taping housewrap - there is a controversy about whether to tape the horizontal seams
  • Rainscreens
  • Solar vapour drive 
  • Vapour barriers and condensation
  • Insulation types and their permeability 
  • Perm rating of a material/barrier
  • Air barriers versus vapour barriers
  • Ventilation - proper exhaust fans, ERVs, HRVs, and dehumidifiers
  • Exterior foam insulation method
  • Steel frames versus wood frames
  • Zip systems instead of housewrap
Do not attempt to become an expert on these topics from reading about them online. There is not enough information online to become an expert in these topics. You simply want to be informed so you can choose a good architect and understand the system they are designing for you. You may also need to learn enough to supervise the build.

Some basic mistakes you can avoid to keep your house as mould-free as possible:

Slats in my loft were a very good idea
  • Window and door flashing not done in a detailed way. Also beware of 0-VOC peel and stick window flashing which doesn’t fit most codes and is not recommend by the companies themselves for the rough openings. I have also seen windows flashed with housewrap tape and not proper peel and stick flashing.
  • Silicone and other caulks skipped where needed on the exterior due to chemical sensitivities.
  • Having air leaks into the wall cavity.
  • Housewrap not applied to spec -  including the overlap and how it is taped.
  • Roof not vented properly (there is some debate here between passive house design and most builders) or double vapour barrier issues in the roof.
  • Putting the vapour barrier on the wrong side.
  • Planning the house to be used with heating but not planning for AC.
  • Exhaust fans over the stove that don’t vent to the outside. Exhaust fans in the bathroom that could leak moist air into the ceiling. The fan I used is pictured (doesn't leak moist air).
Proper exhaust fan. Click pic for link.

  • Not having a professional plumber install your plumbing system. Or reusing old plumbing pieces that could fail on you. 
  • Pipes not designed and winterized for the climate causing them to freeze and burst. Not providing the cold and hot water a low point to drain outside. If the power goes out you will need to drain them. You may also want to drain them if you are away. 
  • Inventing a new wall system that is not normally used. Make sure you understand your wall system and which direction it dries to. Don’t skip on things like rainscreens (if that is the system you are using) just because it is a tiny house. 
  • Using wood that doesn't hold up well to humidity in the framing.
  • Putting your mattress directly on a solid surface with no ventilation under it (use slats or a box spring).
  • Using natural latex. See my warning here
  • Not using a properly sized drainage line on a heatpump. Know how to flush it out, this tends to get clogged with mould.

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