Question from B. C.
Thanks to all your tips, my wife is really feeling much better with her MCS. In fact, we’re now carefully considering putting a tile floor where the carpet used to be in the bathroom adjacent to her bedroom. Using your recommendations we have found safe tile adhesives and grout sealers but we can’t find anything about safe grouts.
Can you recommend any products for a chemically safe grout and are there any problems to watch out for in the cement board underlayment materials?
Debra’s Answer
Grouts can have additives that that can off-gas. Safer brands include Mapei and Summitville-700.
The standard cement board underlayment is fine. Two brand names we have used are Hardibacker and Durock. There is also Wonderboard, which was the first product of this kind.
My contractor knows I am extremely concerned about preventing mold growth, and so wants to use his favorite, WEDI board,behind the tile, but he seals the seams with a product from WEDI. He gave me a sample on cardboard and the smell lingered for weeks. I don’t like it, but can’t say that I am reacting to it (that’s part of my problem–I have symptoms that won’t quit, so maybe it’s something that I am living with already!) Does anyone have an opinion on the WEDI system? He hesitates to use anything else, because he wants to feel confident that it will not leak.
There is another product not used in the states very much. It is Magnesium Oxide board or sheets. There is a Bau-Biologie builder/consultant in Austin, Texas-George Swanson- who can tell you where to get it. Magnesium Oxide is mold-proof and fire-proof and is used very much like cement backer board, only I consider it much cleaner, both environmentally and for humans and much better performing than cement. Mr. Swanson’s contact information is: Contact George at 512-653-8624
Email georgeswanson245@yahoo.com
Website: http://www.geoswan.com
Mailing address: 6705 Hwy 290 West, Suite 502
Austin, Texas 78735
Debra Dadd, I think George would be an excellent speaker for your radio program. His specialty is in building non-toxic homes.
Any grout is NOT OK with those of us who are very sensitive. additives, including biologicals, are added to regular grout. A friend lost her apartment when the wrong grout was used. Sanding the grout out didn’t work; the space had been contaminated beyond remediation.
Many grout products contain anti-microbials, which are used to keep mold stains from showing. Custom Building Products do not use anti-microbials in any of their grout products except on (Fusion Pro). Their products have been used in the Bullitt Building in Seattle, one of the greenest and healthiest buildings in the USA.
If I lay new tile over old offending tile do I lay something down to help cover offensive grout,like a netting. Will the new tile and grout if it’s not a problem for me, hold in the problem grout from before. I’m trying to avoid tearing out the tile and grout.
Juleigh
I don’t have all the information here, but depending on the type of tile, you may not be able to lay the new tile over it. It’s always best when laying tile to start with a clean, smooth surface. Check with someplace like Home Depot for installation instructions and help.
My architect has suggested Schluter Waterproofing Membrane as the barrier underneath our tiled shower. However, we have not been able to determine if this is a healthy product to use or not. Can you comment on that product or suggest an alternative? Thank you!
This is fine. Scheultz Waterproofing Membrane is made from polyethylene, which is a “benign” plastic.
http://www.schluter.com/schluter-us/en_US/Membranes/Uncoupling-(DITRA)/Schluter%C2%AE-DITRA-&-DITRA-XL/p/DITRA
Thank you Debra for your response! I believe that we would be using the KERDI system rather than the DITRA that is linked above. I requested the MSDS on the KERDI and it is an EVA-foil laminated with a non-woven polypropylene. Would you still consider that to be “benign”? A link to the product is below:
http://www.schluter.com/schluter-us/en_US/Membranes/Waterproofing-%28KERDI%29/Schluter®-KERDI/p/KERDI
Yes I think that would be fine.
My contractor just installed wonder board to my bathroom. It was purchased Home Depot the smell is very strong, I am wondering is this toxic or will it go away. I would hate to finish the bathroom and ripped a part because of the smell.
Please let me know If this is safe????
It’s not safe, but if it’s completely encased by mortar and tile, you will not smell it or be exposed to the fumes.
Both ceramic tile and grout are porous. Some sensitive people do react to the material underneath tile and grout.
Has anybody had experience with using either redgard or mapei (or another waterproofing membrane) over a backerboard such as hardibacker or durock. What waterproofing membrane do you think might work well for those with chemical sensitivities?
For anyone with MCS searching for a tile grout, Polyblend has latex additives that are not listed on the MSDS or on the box. The company actually recommends C-Cure for people with allergies or chemical sensitivities.
Those of you who have used the Hardibacker–did it have the “moldblock technology” when you used it? I’m not sure if it always had that feature? The Hardibacker seems to have the lowest odor, but I’m slightly worried about the moldblock thing. Not sure if it’s chemicals they’ve added or what, so I’m a little nervous about it. Although I’ve seen the Hardibacker recommended by some people online who built a very green house, but not sure how long ago. I’m so nervous about which cement board to choose. Our tile installer laid Wonderboard the other day, and had to tear it up because the smell was so terrible I couldn’t tolerate it.Thanks!
COMMENT FROM DEBRA:
I called the manufacturer and they said no changes have been made to the product. The moldblocker technology has been in the product “for many years”. I also looked at theMSDS for Hardibacker and there are no hazardous chemicals in this product.
I assumed that after the ceramic tile is put down that any odors from the backer board would not seep through. Am I wrong? Fixing to install ceramic tile in my bedroom and bathroom.
I’ve laid tile over cement backer board and it had no odor.
Is Permabase cement board ok? My tile guy laid some in preparation to put ceramic tiles on top, it smells so strong I’m having a reaction.
Cement board is a non-toxic material. The MSDS does not show any toxins of concern. It does say that it can have an organic odor that can dissipate. Some readers have reported odors with other cement board. Try lots of ventilation.
P.S. Debra, do you know if the Ditra system for tile is nontoxic and/or if it offgases or has odor? The manufacturer calls it “inert and physiologically safe” but this can vary with people, I’ve come to learn. Thanks.
COMMENT FROM DEBRA:
I had a difficult time finding “the Ditra system.” I found pieces of it, but couldn’t find it all put together.
And as you said, whether or not something is safe can vary with the individual.
If you want me to look at specific parts of this system, please post URLs for the products in question.
Many chemically sensitive people do not tolerate just any grout. Many grout products have chemical additives and polymers that do not outgass quickly, if at all.
I recommend that chemically sensitive people test all materials including backerboard, tile adhesive and grout as well as any grout sealers before using them in your home.
Many chemically sensitive people use a homemade “Thinset” as tile adhesive and make their own chemical free grout.
AFM has a grout sealer that some chemically sensitive people tolerate.
I agree with Patty.
You MUST get samples of all materials that will be used.
Grout and tile are porous and some sensitive people can smell fumes of the underlayment product seeping through.
Many of us react to grout with latex or other additives such as those used to make product dry faster.
can you suggest a company where I could buy a few bags of unmodified grout? I found saltillo from custom building products (just cement and sand) but I would have had to buy 3000 pounds of it. I only need 3 (20) lb bags or less. Thanks for any advice
A reader wrote to me that she had a bad reaction to Hardibacker, though others in her family did not, and I have not. She got them to send her the MSDS for the Moldblock additive, which states that the board is treated with the fungicude oxine copper. Oxine copper is of very low toxicity, however some people do react to it. I don’t believe that oxine copper can permeate tile once laid, or grout, however just wanted to make this known since the information was difficult to come by.