This post covers all of the materials you need to complete a tiling job without the use of toxic materials that offgas VOCs.
When tiling, first we lay usually down a mortar which is almost always a thin-set (not thickset anymore).
We might need to use membranes or special backer boards depending on the project. After the tiles are laid, the grout is applied between the tiles.
A non-toxic grout sealer, which not neccesary, is the final product.
This post contains affiliate links to relevant products that I use and recommend. Upon purchase, I earn a small commission at no extra cost to you.
Non-Toxic Thin-Set Mortar
Thin-set is the bonding layer that goes down under your tiles.
Concrete-based thin-sets are the safest type and are also easy to source.
Thin-set mortar is also known as dry set and dry bond.
Unmodified Thin-Set (no Additives)
An unmodified concrete-based thin-set is concrete, sand, and lime and is not mixed with acrylic latex or vinyl additives.
The unmodified type is recommended for floors and may not be suitable for all applications.
On walls, thin-set usually has some “latex” or “vinyl” additives like PVA, EVA or VAE.
Ceramic tile doesn’t need much polymer additives, porcelain tile needs more.
Consult first with the tile manufacturer; if you don’t get a clear answer on which type you need then look to the advice from the thin-set manufacturer. You also need to consider the requirements from membrane manufacturers. Source, JLC.
Modified Thin-Set
Ideally, I like to see full disclosure on what the polymers are in thin-set.
“Latex” or “vinyl” additives generally refer to acrylic, EVA, PVA, and VAE polymers.
Brands are mentioned in my book and course.
Other Types
Most chemically sensitive folks would want to avoid the higher VOC epoxy thin-sets and most mastics.
Although there are some safe and tolerable tile glues (mastics) like AFM 3 in 1.
This can be used when applying tiles to a backsplash, however, you do need to consult with AFM on whether this will be suitable for your project (dependant on the weight of the tiles).
Non-Toxic Tile Membranes / Underlayment
Over the first layer of thin-set, I used Schluter DITRA (polyethylene with a fleece backing), an uncoupling membrane that will help prevent cracking in my tiny house (it worked well and did not have an odor to me).
Polyethylene is a very safe plastic.
If you just need a waterproofing membrane, use Schluter Kerdi (a modified PEVA core with non-woven polypropylene). (Also at Home Depot).
Membranes for the Walls
For a tiled shower, the Kerdi shower system is recommended by architects to create a mold-preventative shower.
Be sure to test all parts including Kerdi Fix sealant if you are sensitive to chemicals.
With the Schulter system, you generally need to use their thin-set and grout.
Schluter All Set and Schluter Set do contain fly ash (fly ash contains some metals).
Integrated Membrane Boards
Instead of using the membranes over concrete backer boards (backer boards are discussed in this post), you could use Kerdi Board (also available through Walmart) or WEDI Panels (you can mention my name at The Tile Shop for 20% off).
Test for tolerability before proceeding. They will be behind the thin-set, tiles, and grout, which will render them safe for most people with sensitivities.
These integrated membrane wallboards help simplify things by replacing concrete backer boards + membrane with just one substrate that is easy to waterproof and provides insulation to prevent condensation.
The panels are made of non-toxic zero-VOC polystyrene with a plastic membrane already integrated.
Concrete Based Non-Toxic Grout
Concrete grouts are the safest grouts and are generally non-toxic.
You don’t need to go to a green building store for this product, these grouts can be found at all regular building supply stores and online.
You do want to look for a basic concrete-based grout in powder form.
I never use pre-mixed grout.
EVA, VAE and PVA are common polymers (referred to as “vinyl” or “latex” or simply as polymers).
Brands
Brands can be found in my book and course on non-toxic building.
Make Your Own Grout
If you need to avoid all additives, you can make your own grout with Portland Cement mixed with sand, lime, and water for a totally polymer and biocide-free option.
The ratios can be found in the book and course.
What are Grout Additives and Are They Toxic?
Those who are sensitive to chemicals will probably want a concrete-based grout (like those above) and then see which additives if any can be tolerated.
Since additives are trade secrets and polymer is a word that can mean a variety of chemicals (there are over 10,000 polymers that can be used in cement) you will probably have to test them against your sensitivities.
EVA, PVA and VAE are common.
In a patent about thin-set mortar, they say the following about polymers: “any type of conventional aqueous latex can be utilized, it is preferable to use either styrene-butadiene rubber, Neoprene, natural latex, butyl latex, acrylic latex, polyvinyl acetate latex, vinylacetate copolymer, or mixtures thereof.”
Polymers can come mixed in or you might mix them in yourself. Mixing them yourself means you can test the additive against your sensitivities in a more concentrated form, on the other hand, you may not want to test the polymers and the grout until it has cured.
Polymers are added to improve chemical resistance, reduce porosity, improve flexibility, and freeze/thaw stability (source).
You will have to find out when and where you need additives, which will depend on your specific project. I don’t consider most of these polymers to be toxic.
Are Thin-Set and Grout Safe – Why Do They Have the Prop 65 Warning?
Sanded grout and thin-set contain silica (the same substance as glass) which is harmful to breathe in when in dust form; you will see a Prop 65 Warning on every product that contains silica dust.
There may also be other minerals in there that are only a problem in dust form like aluminum oxide, which can result in a high health rating on the SDS and other warnings.
Again, these are safe when it’s mixed wet and when it cures.
Chromium 6 is usually found in Portland Cement (and therefore in grout and thin-set) – that will also trigger a Prop 65 warning. Be sure to take precautions when it’s in dust form.
Some cement has added fly ash (which contains metals) and some don’t. Check the SDS sheet of the grout or thin-set to check for fly ash.
Use an N95 mask (or better) when mixing grout or thin-set until it is fully wet. Avoid getting wet cement products on your skin. It is safe once in solid form. A grout sealer listed below is an extra form of protection against dusting of cured cement products.
Non-Toxic Thick-Set /Thick-Bed Mortar
Thick-bed mortar (also called thick-set or mud-set) in its most basic form is simply Portland cement and sand.
Custom Building Products makes a mix of 1:3 that is unmodified, it contains no chemical additives like polymers.
This is harder to source than thin-set.
Alternative to Concrete-Based Grout
For something more waterproof check out QuartzLock; this won’t be tolerable for everyone. It is a urethane-based grout, not cement, and provides more waterproofing.
There are also acrylic-based premixed grouts that have some off-gassing.
Epoxy grouts are also waterproof, and may be selected when a clear grout is specified.
I personally would not use a premixed grout in a chemically sensitive person’s house and I would keep a close eye on contractors to make sure that they use what you specified and don’t swap that out for a premixed option.
Your waterproofing needs to be done properly behind the tiles.
Non-Toxic Grout Sealers
For a full review of all the grout sealer types (and where to use each kind) see my dedicated post on grout sealers.
In many situations, you don’t need a grout sealer, or you could even do more harm by blocking moisture.
If your situation does call for sealers to be used, the post on grout sealers will walk you through each type.
Corinne Segura is an InterNACHI-certified Healthy Homes Inspector with certifications in Building Biology, Healthier Materials and Sustainable Buildings, and more. She has 10 years of experience helping others create healthy homes. You can book a consult here.
mmc
Can you recommend any of the following cement based grouts?
Prism, Polyblend and Rapid Set Cement All
Thanks:+)
How can I find the other ingredients in these products that aren’t on the Product Safety Data Sheet? The only toxic ingredients I can find on these is Carbon Black and Formaldehyde.
Melissa
Don’t see a brand name for the non-premixed grout you recommend above. We have to regrout the outer edge of the bathroom tiles due to mold/mildew growth that won’t come off with treatments or brushes. It only mentions that you can find the specific brand name in your book or online course. I tried to purchase your book to find out the product name but it only came in Kindle form and I don’t have one. Can you post here the specific brand name for the grout you recommend or at least a link to the book I can buy to find out the Brand name (non-kindle version)? Thanks:+)
Corinne Segura, Building Biologist
hi, the kindle version can be viewed from a regular computer you dont need a kindle device or special app on a computer
Rebecca
Recommendations to re-grout unsealed brick flooring in kitchen? Could def use a new coat and wanted to find the least toxic option.
Yvonne
We are installing porcelain tile in our kitchen. We live on an island in Maine, right next to the water, so the environment is very humid in the summer and cold in the winter. We usually leave for a few months during the winter, and the house remains unheated while we’re away.
I have chemical sensitivities, and I’m trying to determine the best approach to prevent tile cracking during the cold months when the house is unoccupied.
Based on your recommendations, I’ve purchased the following materials:
Schluter Ditra-XL
Custom Building Products Non-Modified Thinset Mortar
Polyblend Plus Sanded Grout by Custom Building Products
However, I’ve read that in climates like ours, where there are significant temperature swings and potential movement in the floor, a flexible, highly modified thinset and flexible grout or grout additive are recommended.
Given our specific conditions and my sensitivity to chemicals, do you have any suggestions for how to proceed?
Do you have recommendations for grouts with natural mineral additives or lime-enhanced grouts that offer some flexibility without relying on synthetic chemicals?
Thank you.
Corinne Segura, Building Biologist
I would need to look at that in a one-on-one consultation.
Yvonne
I will set up a consultation and send this via email. Let me know if there is any other info you would need for me to include.
Yvonne
I attempted to schedule an appointment. There are no available appointments showing this year for any category.
Jessica
Do you have any recommendations for mastic for sealing HVAC systems? We are getting a new HVAC system and they need mastic to seal some of the components.
Thank you!
Corinne Segura, Building Biologist
no sorry I don’t cover HVAC materials
Ellen
Our laundry room is off the kitchen and we will be installing a limestone tile (4″x12″) floor. Proposed is the Ditra underlayment with Laticrete 253 Gold White Thin Set. I feel like there is a 0-VOC product that would be better than this product which claims to be low-VOC.
Please advise on the best, healthiest thin set for this material. Will Ditra be a healthy choice or do you prefer an alternative?
Thank you for your advice!
Corinne Segura, Building Biologist
thinset brands are in the book
Ellen
Would it be possible for you to please list your top 2 choices as the work is starting tomorrow! Thank you!
Ellen
It would be healthiest adhesive I’m looking for rather than grout sealer. Thanks very much.
Bri
We have an old slab without a vapor barrier below it. I am going off Cheryl Cieko’s advice to do tile so the slab can breathe through the grout. But if we use the Ditra membrane, is that creating a vapor barrier and not letting the slab breathe? What should be used instead in this case?
Corinne Segura, Building Biologist
yes that is a vapor barrier, it’s hard to find a breathable one for under tiles, see article on underlayments
Fred Lewis
The tile I am interested in requires a latex modified thin set. Due to my sensitivity, I am looking for a latex modified thin set that is VOC free. Is there such a thing and if so, could you recommend a brand to use?
Corinne Segura, Building Biologist
yes they are in the article
Crystal Johnson
Do you have a recommendation for an epoxy based grout that is PFAS free?
Corinne Segura, Building Biologist
i would not use epoxy grout generally, though it probably doesnt gave pfas, it offgasses and has biphenols
Jane Sussman
Hello,
How do I purchase your non toxic grout?
Katharine Egan
Hi Corinne,
THANK YOU for this site and your work in the world. I’d appreciate any input you might have:
Moisture meter revealed areas of 100% moisture on apartment tile shower walls, especially around faucet / faucet handle. Wall behind tile is probably green board.
On MON 8/12, management wants to seal two 2 inch areas of missing grout with non-breathable caulk. But WE want to seal in as little moisture as possible.
1) Should I say OK to this (if the alternative is a delay of days or weeks in getting these grout areas fixed)?
2) Is it worth advocating for using unsealed grout instead (even if this creates a delay in the patching)?
3) Short of full remediation (for the mold I presume is behind shower walls), what can I do to make it safer to live in this apartment? (I had a physical reaction to dehumidifier, but we do use a bathroom exhaust fan & air purifiers. Apt has HERTSMI of 0-10, depending on location.)
I have extreme health consequences to even tiny amounts of mold exposure. Can’t tolerate remediation or even removing tiles to check for mold.
Thanks in advance for any guidance.
Warmly,
Katharine
Corinne Segura, Building Biologist
greenboard is not for behind tiles. behind grout is mortar, behind mortar is a waterproofing layer, behind that is a wall board but not drywall. only at the penetrations is it possible for the hole to go all the way through all these layers. caulking around the faucet and handle is necessary. if there is a deep crack in the grout I don’t know of any reason you can’t caulk that.
Katharine Egan
Thanks, Corinne, for your quick reply!
I DEEPLY appreciate the advice & would be very grateful for a bit more info:
1. I realize that for years, there’s been missing/inadequate caulking around faucet (it’s loose and not sealed to the tile) and maybe faucet handle (doesn’t appear to have ever had caulk; seems to be cemented firmly to tile from inside the handle).
So, I’m thinking water got in around the wall/faucet and wall/faucet handle junctures, and this is why the moisture meter says 80-100% in several spots in this area–especially below and to the sides of the faucet and faucet handle. (I doubt the moisture meter’s reacting solely to metal piping behind the walls b/c there are several high readings over a 1.5’ span.)
QUESTION: Should we caulk around the faucet and faucet handle now? (We’d prevent more water from infiltrating, but it seems would also seal in moisture, which I’m afraid to do.)
2. Moisture meter also shows many high readings (32-several 100% places) along the tiled shower wall in the 10’’ above where the tiled wall meets the tub.
(No faucet or other penetrations in this wall, except for wall fan hole which is so high no water can reach. Juncture between tub & wall appears intact (was redone a couple yrs ago because it was gray). There is only one tiny (millimeters) hole in the grout above this high-moisture-reading area.)
QUESTION: Is this normal for the bottom of a tiled shower wall?
QUESTION: What do you think the chances are that we have mold behind the tile with moisture readings this high?
QUESTION 3) Are you saying it’s safe to caulk a few small grout holes b/c they’re so small that any sealed-in moisture will hopefully evaporate through the rest of the grout? (Rest of grout was probably sealed when building built 12 yr ago, if that’s standard building practice).
THANK YOU in advance for any advice. This is supremely stressful, and I appreciate you very much.
Corinne Segura, Building Biologist
I would do a consult with Cheryl Ciecko
Katharine Egan
Thanks, Corinne. Unfortunately, I don’t have time for that this time because management is insisting on doing this tomorrow morning. But I will consider it next time.
Because time is short, if you’re able to clarify the input you kindly provided earlier, that’d be great: Are you saying it’s safe to caulk a few small grout holes b/c they’re so small that any sealed-in moisture will hopefully evaporate through the rest of the grout? (Rest of grout was probably sealed when building built 12 yr ago, if that’s standard building practice).
Thanks again for your website and your help in this post! 🙂
Corinne Segura, Building Biologist
it depends on what you mean by grout holes. I can’t comment beyond what I shared in the last comment with the info I have on this and with the amount of help I can offer in the comments.
Whitney
Hi Corinne, Thank you for all your work; your site is very helpful. I tried to comment on the grout sealer post, but was going back and forth with this page and I’m not sure it went though.
I like your rational for not sealing grout. I am wondering, though, if unsealed grout will breakdown a little through the years causing the dust to be airborne. If one needs to wear a mask when mixing grout due its harmful nature, is this a concern for the product with product wear and tear?
Thank you.
Oliver
Hi Corinne.
I’m going to use Schluter’s Ditra system to accommodate some large format tiles. Based on your recommendation here and endorsement of it others, I was going to use Ardex 5 thinset. However Schluter are recommending their Kerdi Koll L which is a two component acrylate that claims to be solvent free. Is it suitable for someone chemical sensitive? I’m rather suspicious of it. Also is there an Ardex grout or grout alternative you could recommend? Thank you so much!
Corinne Segura, Building Biologist
I wouldnt use a premixed grout or thinset, though you do have to make sure you use the right kind of grout and thinset for your tile type, grout thickness and backer. I can’t advise on which one is best you need a tile expert for that.
Oliver
So is the Schluter Kerdi Koll L suitable for people with chemical sensitivity? Or is Ardex-5 the better option?
Corinne Segura, Building Biologist
I generally would not use a premixd mud, but i have not done a review of the Kerdi Koll L. I can’t do a full product review in the comments, but this type of product is not usually used by the chemically sensitive.
Carol
Hi Corinne!
Do you know if Servoperl royal made by Kiesel is safe and non toxic grout to use? It states that it has zero VOC’s, however I realize it could still be toxic and a problem for people with chemical sensitivities. It’s a German company.
Thank you!
Corinne Segura, Building Biologist
I don’t know German companies but if you compare it to the ones on the list in terms of ingredients than that will work
Carol
Thank you! The SDS lists calcium aluminate cement, Portland cement, titanium dioxide and quartz (silica). It’s similar to others.
Corinne Segura, Building Biologist
that’s not a complete ingredient list, it’s just the parts that are hazardous to breath in when installing it
Michael
Great question, Carol! It’s always important to double-check product safety, especially when dealing with grout and other materials
Jackie
I am installing a quartz/marble MSI backsplash in the kitchen and around my gas fireplace. What thin set mortar, grout and sealer do you recommend that have zero VOC and safe around food with preferably a Greenguard Certification? Thank you!
Corinne Segura, Building Biologist
All of the concrete based grouts and thinsets I recommend are safe as a backsplash and are 0-VOC, greenguard is not neccesary for any concrete based grouts. Might be helpful on any premixed grouts.
Anne-marie Skolaude
Hi,
I am redoing the tile in my basement laundry room and hoping to add electric heat below the tile. With a cement slab I know we want to let it breath in. Is there a problem with mold development underneath the underlayments. We are likely using a schluter system.
Thanks so much
Corinne Segura, Building Biologist
Yes that can be a problem with plastic underlayments https://corinnesegura.substack.com/p/mold-preventative-flooring
Coral
Hi! Is there a product you’d recommend between Mapei Ultracolor and Mapei Keracolor? I’m having a hard time understanding the difference in toxicity. They both seem to be 0 VOC.
Corinne Segura, Building Biologist
Mapei Keracolor looks good, I have looked into that one and have more details on it in the article. I have not looked into Mapei Ultracolor so you would have to ask if there is a biocide, because it says stain resistant i would ask about PFAS, and about fly ash too if any of those are on your list of concerns.
Hailee
Will these grouts work with any tiles? I am having Daltile installed (thanks to your lead free tile article!). Wondering if the installers will be okay with using a grout recommended here, or if they will want to use what Daltile recommends.
Corinne Segura, Building Biologist
not all grout and thinset work with all tile, there is a secion in the article about that
Kira
Hi! Do you foresee any issues with the Custom Building thinset Versabond? It seems that it has the same materials as the thin set you recommended in its SDS. or would you be concerned about the additives? Any advice you have would be so appreciated! Thank you!
https://www.homedepot.com/p/Custom-Building-Products-VersaBond-50-lb-Gray-Fast-Setting-Professional-Thinset-Mortar-MTSG50/100162542
Corinne Segura, Building Biologist
The polymers are not likely concerning but I don’t know what they are in that so I dont know for sure.
Don Davis
Under “Non-Toxic Tile Membranes / Underlayment,” you write, “Over the first layer of thin-set, I used….”
Do you mean, “Under the first layer….”?
If so the present wording is very confusing!
Also, I puzzle about “first layer of thin-set.” Is a second layer commonly (or ever) used?
Corinne Segura, Building Biologist
there is thinset under and over the ditra
Jennifer
Is there a grout that is better to use in the shower compared to what is used for a regular tile floor-or would it be the same? My husband is going to be replacing some grout in the shower and was curious before we bought anything. Also, we don’t want to seal the shower with a sealer afterwards correct? That way it will dry from the inside out? Thank you so much!
Corinne Segura, Building Biologist
yes that is correct, the same options are used in the shower depending on tile type, size, grout width, and waterproofing layer.
Jennifer
The polyblend when I click on it says floor only, but the polyblend plus does say for showers? Would the plus be ok to use? We dont know what was used before or what is behind the tile waterproofing wise.
Corinne Segura
Plus is safe, it’s in the article
Kara
Hi there! My tile installer is recommending this thinset:
Custom Prolite Thin-Set in White
https://www.bedrosians.com/en/product/detail/custom-thin-set/?itemNo=CUSMRT-PLW-30
What are your thoughts on toxicity? Would this be safe to install in an basement area where children will play?
Corinne Segura, Building Biologist
i cant do a full product review in the comments but i would want to know what the post consumer recycled content is to start
Deborah Santor
Have you looked at Mapei Ultracolor Plus? What are your thoughts for use in bathrooms.
The Ultracolor Plus cures in 3 hours. Does that mean no more offgassing after that time?
For the Keracolor U or S, sealer is recommended and for bathrooms I imagine this would be an important consideration given how moldy things can get in these areas.
I am not chemically sensitive, I am just trying to limit, as much as possible, the amount of toxins I am exposed to with my 5 room renovation (2 baths).
I would appreciate any information you can provide.
Corinne Segura
I recommend the breathable grouts in the article for almost all purposes unless it’s a table or countertop or something like that as per recommendations by Cheryl Ciekco and other experts. The grout needs to be able to dry out unimpeded.
Brigid
Corrinne, would you tile an outdoor screened patio on the existing concrete pad with or without the Schluter Kerdi ? I does get wet a lot both from the marine layer but also from outside intrusion when it rains.
Corinne Segura
i think you will have to talk to a contractor about that
Brigid
OK, thank you
Brigid
So, I talked to my contractor and he advised Aquaguard which I’m sure is very toxic. He is fine doing the Kerdi if I want it.
I just don’t know if it’s better to protect the tile from water seeping up from the concrete below, or if its better to let it air out through the grout. (The tiles themselves will be sealed on the top.)
Corinne Segura
the membranes are used to decouple the two substrates and stop cracks from telegraphing through. Whether you need it for that or whether it’s a good idea to block moisture at that layer, I don’t know.
James Pratt
From my personal (nightmare) experience, whatever you do, avoid using Miracle Sealants brand grout and tile sealer products. Biggest mistake of my life bringing that into my home. It caused me horrible respiratory problems and the offgassing lingers for years.
Cindy
Thanks so much, Corrine!
Cindy
I just replaced a horribly fume-y PVC bathroom floor with ceramic tile. I followed the advice in this article and chose only products that were recommended on this site. Within just a few days, the bathroom is finally normal again! No fumes anymore, not even from the new installation! I still can’t get used to walking into the bathroom and being able to breathe. THANK YOU SO MUCH for sharing all of the amazing information on this site; I would have spent weeks trying to products to use otherwise!
My last lingering issue (literally) is that the fumes from the PVC floor seem to have permeated the entire vent system from when the PVC floor was still there. (The small cottage I live in has a furnace, which also has a “fan” setting when I just want to circulate the air/no heat.) So now, stinky/irritating PVC fumes are still present in the vents. 🙁 I never would have even thought that this could happen. Other than running the air fan/heat, is there any other way to clear out those fumes?
Corinne
You could get a duct cleaning from a reputable company but be careful as there are a lot of scam companies. And also this will only clean the dust that is in the ducts. You may have had VOCs get absorbed in various porous materials.
Stacey
I am exquisitely, chemically sensitive and have trouble with cement-based products or stone-based product for that matter. We have a tile that I know we need to take out, possibly 2 b/c The grout has cracked over the last two years and I can smell mold behind it where it – What kind of grout would you recommend for the most sensitive people? I need one that cures extremely fast like dries as fast as anything else out there. Please help. And thank you so much for all you do!
Corinne
you’ll want to test some options on this list before proceeding. They don’t dry super fast because they are concrete. But it’s way more important to make sure your waterproofing is done correctly, especially behind showers, as mold is way more important to avoid.
Sam
Hi Corinne, thank you for this super useful information. We are in the middle of a renovation project and wanted to check if Custom Building Products’ AcrylPro Professional tile adhesive is a safe product to use for an indoor application. Thank you for spreading knowledge about safe products.
Kate
Thank you, Corinne! Your posts on flooring have led us to wood-look tile for our son’s nursery and the two other bedrooms on our one-story concrete slab house in a humid climate. The tile is porcelain, and the custom blend standard grout that you recommended calls for adding Admix to the mortar for porcelain. On the company website. Mapei’s unmodified mortar also calls for adding a polymer additive for porcelain. I’m wondering then if those are then comparable (with the additives added for porcelain) to buying Mapei large floor tile mortar that mixes with only water and is already modified. The safety data sheet on Mapei’s website says the modified large floor tile mortar is 0g VOC per L as an application property and voc content 0 and TVOC range less than 0.5 mg/m3. It also has the Indoor Advantage Gold. It shares the ANSI A118.4 & A118.11 with the custom blend standard when Admix is added. I plan to use the mapai grout you listed on the post as a safe grout option and luckily it’s also recommended by the tile manufacturer for that tile. Is it better to stay consistent with the brands in matching mortar and grout for porcelain (as it seems I need some kind of polymers for porcelain in general)? Is the mapei large floor tile mortar worse than the standard mortar with the Admix polymer or mapai additive added to the standard mortar? Thank you so much for helping us! Kate
Corinne
Any modified grout or mortar that is 0 VOC is great in my opinion. The usual additives in those are very benign. I have not tested out for myself the admixes that you mix yourself so I don’t know as much about them.
Kate
Thank you so much, Corinne, for sharing your time, help, expertise! All of your posts have helped us tremendously in making these decisions for our family and home. Thank you! Thank you! Kate
Corinne
you’re welcome!
Joanna
Hello
I am looking to install small marble tiles on a backsplash. Do you know if the AFM almighty adhesive would be suitable?
Thanks
Corinne
It’s not a mortar and is not meant for installation of tiles, I’m not sure what would happen if you used it that way. I would use a concrete based mortar or AFM 3in1 if the tile are lightweight enough. You would have to ask the company if that will work with your tile.
Beth
Hi, I have the same question as Alex. In a prior post you said you would recommend polished concrete or tiles with breathable grout for basement slabs so the concrete can breath. In this post you mention a waterproof underlayment for tiles which would not allow the slab to breath correct? Trying to choose a flooring for my basement and I’d like if you could let me know the best option.
Corinne
Yes correct, the most common underlayments are not breathable. In the post on underlayments there are two options that look to be breathable.
Rachel Quigley
Thank you for your informative articles. I see that Custom brand grout carries a Calif Prop 65 warning for reproductive harm that is not from inhaling silica during installation:
WARNING: This product can expose you to chemicals
including crystalline silica which is known to the State of
California to cause cancer and hexavalent chromium
compounds which are known to the State of California to cause
cancer and birth defects or other reproductive harm.
The Calif Prop 65 website says hexavalent chromium can be inhaled through dust but also ingested by touching it and putting your hands in your mouth, as children often do. I know that lead crystal produces lead dust over time. Might grout produce hexavalent chromium dust over time that could harm people, especially children?
I cannot ask my tilers to make their own grout. Is there any brand that does not have hexavalent chromium?
They are supposed to start grouting tomorrow, but I will try to delay them until I hear back from you! Hoping to hear soon. Thanks much! -Rachel
Corinne
Thank you, I added that to the section on prop 65 warning. Portland cement itself usually contains chromium 6, so that can’t be avoided in any concrete based grout or thinset. A silicate based grout sealer will stop “dusting” of the finished product.
Res
Thanks for this valuable information. Is white thinset mortar (Custom Building Products Standard CustomBlend) more toxic than grey as it has more additives to achieve white color? Appreciate a response.
Corinne
No that is fine. Neither one should be breathed in when in dust form. Both are the same once in liquid and curd.
Tammy Wigington
I have a dilemma. We have just purchased a home that has 2 of the bedrooms in the basement. The house was built in 2010 and all of the flooring in the basement is vinyl. My son is 18 and has autism and extensive food allergies. One of my main concerns is the plasticizers and phthalates. I had considered pulling the vinyl up (about 1300 sq ft) but was wondering if it would emit more phthalates if it was ripped, cut and torn to pull it up. It is glued down vinyl squares. Do you recommend pulling it up or putting something on top of it? I’ve read that hardwood isn’t recommended for basements. I’ve looked at non toxic or low voc engineered hardwood that is approved for basements. The basement is walkout on one side with 2 sets of French doors and 5 windows. I’d be glad to pay for a phone consult. Thank you for your help.
Corinne
I would pull it up but you’ll have to see if it can be peeled up or it’s going to crack. If it’s going into a dust you can put it under basic containment.
Alex
Hello Corinne,
Wow, Great info! I am confused about something. You’ve mentioned in other posts that over concrete slab you only recommend tiles or polished concrete. The reason is that it is more breathable and other materials might require a vapor barrier, which can cause mold to fester. In this post you recommend an underlayment under tiles that would also act as a moisture barrier. I might be misunderstanding, can you clarify?
Nadia
Thank you to Corinne for this valuable information. I have the same question as Alex.
Gary
On the bottom behind kitchen cabinets there is an open space that I need to close to prevent roaches from coming from the apartment below. Should I use concrete? If so, what kind should I use? What else might work?
Thank you
Jill
How bad are antimicrobials in grout? My contractor is recommending Bostik Vivid grout because it has the sealer mixed in and lasts forever. It’s zero VOC so from what I can tell the antimicrobial may be the most toxic thing about it.
Corinne
I mention them in the post, we expect that they are nano silver which isn’t particularly toxic at least not in this application/form.
Mamta Borkar
Hi Corinne,
Thanks for all the helpful insight into tiling a bathroom. Appreciate your knowledge & help.
We are planning on tiling our bathrooms and using Porcelanosa tiles:
1. AMSTERDAM HEXAGON GREY BPT 19X19X1,4 – wall tile
2. ALEXANDRIA WHITE MATT 33X66(A) – floor tile
The grout they recommend is –
1. COLORSTUK RAPID MANHATTAN N 5 KG
100236464
GROUT FOR AMSTERDAM GREY HEXAGON TILE
2. COLORSTUK RAPID BLANCO N 5 KG
100236463
GROUT FOR FLOOR TILE ALEXANDRIA WHITE MATT
Can you please provide some guidance into if these grouts are safe to use? This is for my kids bathroom, so wanted to be sure before the purchase.
Also, both these are portland cement based grouts.
Your guidance is greatly appreciated.
Thanks,
Mamta
Corinne
If I can help you one on one with reviewing products I offer email consultations that are booked online https://app.acuityscheduling.com/schedule.php?owner=19257501&appointmentType=16364655
Suzmiché Morris
Hi, I am preparing to tile a kitchen backsplash over freshly hung, textured, and painted drywall. I’ve extensively read your instructions on tiling a countertop to learn the least toxic way to accomplish this project. Your posting on thin set and grout is helpful, and I have the AFM tile sealer. Now I am wondering if you know of a non-toxic primer sealer to put on the dry wall prior to the mortar? An alternative to Prime Grip perhaps? Or do you know if the primer may not be necessary since the wall is textured?
Corinne
Normally it is primed yes. Not sure about the textured element and how it changes things. It’s normally a standard new wallboard primer, so which ever brand you like there will work. I like ECOS, Farrow and Ball and Ben Moore. More in the paint post.
Jennifer
Hi! Is the afm 3 in 1 what you could use for marble backsplash in the kitchen? My contractor said he uses mastic, so I came here to check. Will try to buy something safe for him to use.
Corinne
It depends on the weight of the tile, you can ask AFM. Otherwise you can use regular thinset and grout.
Jules
Great guide, many thanks!
Unfortunately we can’t seem to track down these products, or equivalents, in the UK. I wonder, do you know of any, or of anyone who may know of some?
Corinne
The basic formulas will be the same there but I don’t know the brands there. It’s more than a full-time job to keep track of them over here!
Lori
May I ask what cement tiles you got from Morocco? I didn’t find it specifically mentioned in either of these posts. I’m trying to get my contractor all the information he needs to not blow me off for being so specific about every little thing.
Thank you SO much for all you do.
Corinne
I had to order those from Morocco because they were not that popular at the time. I don’t remember the brand it was quite a while ago!
C
Hi, which Mapei Kerracolor is safe?
The seem to have Kerracolor in FF, GG, SF, and Flex varients?
Many Thanks
Corinne
I have looked at Keracolor S and U (sanded and unsanded).
Heidi
I am just realizing that I am chemical sensitive with our most recent remodel. Prior to my realization, we have already purchased our tile, mortar, grout and sealer from the Tile Shop. The products we purchased are the SUPERIOR PRO-GROUT EXCEL and Ardex X5 Flexible Tile & Stone Mortar 40lb Gray. Haven’t found the receipt for the sealer yet. What are your opinions on those products? I am not familiar with chemicals, so based on SDS I am thinking the silica dust is the biggest problem. Not sure on the off-gassing. Please assist.
Corinne
I would have to look at that.
Jamie
Hello!
Our tiler is wanting to use LATICRETE PermaColor for thin-set and grout. I saw you recommend the Laticrete brand, but maybe not all their products. This one that he wants to use, in particular, has antimicrobials. I understand it to help prevent mold–but are there major concerns with this additive? Any suggested alternatives?
Thank you for the help!
Diane
I like the idea of Kerri board for bath, and I see you mention the Kerdi fix, And have you gotten any feed back on the Kerdi Fix and the Kerdi thin set? And thoughts on using that, I realize its a personal thing depending on peoples sensitivity but wondering Safety wise ( toxic wise) your thoughts on this
Did you hire workers to put in the Kerdi board or was it a do it yourself project.?
Corinne
I have used the membranes myself but not the boards. Kerdi Fix and thinset have been well tolerated by most but definitely I would test them.
Cheyenne Hanes
What do you think about forbo marmoleum 885 adhesive, how safe is it compared to the ones you listed!
Corinne
On paper it looks fine.
Cheyenne Hanes
very glad i came across this page, we have a baby and are looking to redo the vinyl to tile and was wondering what your opinion was on which brands would be less toxic(no vocs and other harmful chemicals to babies)for us to use! need help picking a back board, mortar/thin set, grout and a sealer if we need it. hoping you could help! thank you.
Corinne
Brands are listed here. There is also a post on bathrooms with backerboards and tiles.
lela
Does Schluter (same brand as the ditra you used) all set (their thinset) contain vocs? I would like to use it, because if you use both ditra and their brand thinset there is a lifetime warranty. However I haven't been able to find online if it contains voc's.
Corinne
ALL-SET is modified so it contains unspecified polymers. They don't list the VOCs but it would likely pass as 0 even though the super sensitive cannot tolerate many or all polymers.
Diane
Hi Did you yourself use the kerdi board Kerdi fix or have you gotten any feedback on this. I see how you said some people are more sensitive its pretty much testing for yourself to see. Also with the Kerdi Thinset ? Yet just wondering any feed back you have gotten if most do ok with it, it does up that warranty . And your own thoughts on this.
Did you do the tile work in your bath yourself with the Kerdi board, or did you hire a professional?
Phil Hyland
Hi Corinne
I am also considering Schluter ALL-SET, just like another person in this thread (lela above). I am trying to decide between Schluter ALL-SET and Schluter SET (which is the product you recommended in your link above).
I need to make a decision for a person who is currently too sick to test products.
Is Schluter SET a lower risk or are the two products comparable from a chemically sensitive point of view?
PJames
Corinne.. you suggested avoiding latex and acrylic additives in thonset. I noticed when looking at the MSDS sheet for Benjamin Moore Natura paint that the base is acrylic latex, can you explain the difference. Can all be most confusing.
Corinne
Many people cannot tolerate the acrylic paints at all though I suggest the ones that are 0 VOC and best tolerated. The additives in grout are not disclosed so I can't do a direct comparison between the ingredients. But some very sensitive people would have trouble with acrylic.
truth naked
Also I read somewhere on this blog that polystyrene is a safe material to use. An article I read on treehugger.com written by a PhD chemist appears to state otherwise… yet the alternatives suggested are also not green.
Corinne
I consider that to be a safe product other than the flame retardants. Discussed in detail in the post on insulation. Not sure which article you are referring to though. In terms of environmental effects it's not considered the greenest product but I look at effect of its use in homes.
truth naked
This blog is so informative, but the grout recommended above says on the back of the package that I contains chemicals known in state of CA to cause birth defects or something to this effect.
Corinne
Silica. In dust form it is harmful. Don't breath it in in dust form just like any product containing silica. Completely safe once dry. Glass is silica. Think of glass in solid form.
truth naked
Premixed version of same exact product says the same.
truth naked
Premixed version of same exact product says the same. Is it just as safe to get the Premixed one then?
Corinne
I wouldn't use the premixed version because of the VOC levels. The California warning is on Ethylene Glycol/
Diethylene Glycol Monobutyl Ether
Unknown
What about caulk? Is there a completely nontoxic zero voc one I can use around my bathtub where the water will be touching it every day?
Corinne
I have a post on that
truth naked
I couldn't find it. Can you please direct me to it somehow?
Also, why doesn't polyblend advertise their grout as non-toxic? Also, I have old tiles in my apartment. They were put there 67 years ago when the building was first built. When I said this to the worker at home depot he said I have to get the non-sanded grout for the area around my bathtub, saying sanded is usually used for floors. I bought sealer from green planet paints. How does this sealer compare with the one you recommended? Thank you.
Corinne
Here it is https://www.mychemicalfreehouse.net/2013/09/chemical-free-glues-and-silicone-caulk.html
I do not know of a sealer by Green Planet Paints. Send me the link that you have.
A lot of products that were never toxic don't advertise as such. The same thing goes for drywall mud and until recently drywall too. I suspect certain grouts will seek green certifications soon.
truth naked
Thank you. Your posts are very informative and useful.
I couldn't copy the link here, but if you go to http://www.thefirstgogreenstore.com and once there click on green coatings and toppings you'll see the description.
Greenplanetpaints.com is their sister site.
RamblingRose
How have the tiles held up after moving the TH? any cracking of the grout?
Thanks for the informative article!!
🙂
Corinne
No, no cracking after the move!
The Kremers
Hi,
I already have QuartzLock urethane grout. Do you think that product would be okay to use to re grout bathroom tiles?
Corinne
It has a VOC level 35 g/L, so up to you. That is low VOC.
Mboris
Very informative post and site. Thank you for sharing.
One of the issues I have is finding mortar and grout that are low in VOC as well as chemical exposure but at the same time without any ingredients labeled as carcinogens. Every product that I have found contains some carcinogen or toxic ingredient. Are there any alternatives that you have found on this. Silica sand seems to be the primary issue on the most used ingredient across this products. Hope someone has found an alternative product(s) that they can share.
Corinne
Silica is only harmful when you breath in the dust otherwise it does offgas anything at all (i.e. glass). You could use a really good respirator and stay away when the mortar is being mixed
Unknown
I had the same concerns reading the MSDS of the products. Happy to hear once cured …. that is safe.
Melody
Find the least toxic mortar and grout possible and then use a sealer like AFM SafeCoat Grout Sealer, or even their Hard Sealer and Safe Sealer products, concieved especially for stopping off-gassing. They seem to be 0 VOC , formaldehyde etc.
There surely are other eco-sealers available if you check, so it can be an effective solution for the off-gassing as well as mold prevention for grout, since mold is also a carcinogen and super-toxic in many other ways.
Anaphylaxing
Pretty tiles! Great post.