Question from MK
I called customer service at Custom Building Products today and by luck ended up talking to someone with experience installing tile for people with MCS.
He told me not to use any standard grout but instead a mix of 2 parts sand and 1 part cement. I considered it, but since this is an apartment installation, I don’t think that would be allowed due to installer warranty issues and higher risk of cracks developing.
The conversation worried me though as he said that the sand and cement method is all he could recommend based on his experiences with MCS.
I’m wondering if you’ve recently used the Custom Building Products Polyblend grout (around 2008-09). I’ve read of some people having problems with polymers, but the polyblend worked well for you for your 2005 bathroom remodel described in your e-book. I’m worried there might have been some formula changes so if this product has worked for you recently as well, I’d feel more assured.
I’m also considering Laticrete SpectraLock, which is the only Greenguard certified brand, and C-Cure since other MCS resource sites recommended it. I recall someone saying the C-Cure needed to be offgassed for a week though :/ .. at least a week isn’t too long and I intend to do at least a 5-day bake out anyway.
Whether modified with polymers and biocides or not, all the pre-mades have been enhanced with ‘special chemicals.’ I’ll just have to rely on experience here 😉
Debra’s Answer
We’ve used Polyblend within the last year and had no problems with it. I don’t know what the “special chemicals” might be. We’ll use it again as we continue to remodel our kitchen.
The cement/sand blend would be the least toxic for sure. But I don’t experience the Polyblend as being toxic.
Readers?
I talked with a tech rep from Custom Building Supplies this week. He said that the Polyblend grout contains a latex additive that is proprietary. This is not listed on the MSDS or in the ingredients list on the side of the box! I’ve seen proprietary additives listed on other MSDS’s, so not sure why Custom didn’t include it. We’ve already grouted a bath and laundry room with it. Now we need to grout a living area, bedroom, and office. We aren’t living in this living space yet, so not sure if I will react to the Polyblend in the shower with my MCS. The rep recommended C-Cure for people with allergies and chemical sensitivities. We are going to give this a try.