Cut it outside or score and snap vs cutting with a saw. There are other options such as cement board or even modern foam based boards.

By the way there are warnings right on it about wearing respiratory safety equipment and the amount of dust created when cut with a saw.

They probably recently cut it sending the dust into the air. Once it's properly waterproofed, sealed, and tiled you shouldn't notice it. That material has probably been in most bathrooms you've been in so if you haven't noticed a reaction before I wouldn't worry.

Aren't Durocks those things that're always chasing Dr. Who?

Thx friends. I didn’t cut it. It was recently installed.

HU-870157674

Hi,

The point they were trying to make is that the installers probably cut it with a saw in the bathroom and created dust - not that you personally cut it.

It's cement and cellulose - and probably has some fiberglass mesh reinforcement. It doesn't off-gas but the dust can irritate your lungs and installers risk silicosis if they breathe the dust often. The instructions say not to cut it with a saw without adequate dust collection. It's no more toxic than concrete.

When they clean up it will remove the dust.

Mrs. Pete:

It will be covered with a waterproofing and tile and should not be an issue.

OK, how about if I just asked for sheetrock instead. That's it. Framing, maybe some plywood and then sheetrock. Paint. Tile. What's wrong with that? How did they do it a hundred years ago?

Umm, no. You need a tile substrate that is stable when it gets wet. That's not drywall.

So you've had lots of people explain the situation - Is there more to it that we aren't understanding? (Like are you reacting to something other than the durock ?)

I don't know. I don't think so. I'm quite sure it was the Durock that caused the bad irritation and uncomfortable respiratory symptoms. And headache (though that could've been the stress but it was new.) Just looking for advice and guidance from experts, industry people and homeowners. Is there some other tile substrate that is stable when wet that won't spew toxic dust into my home? Thanks Jake and all.

"Is there some other tile substrate that is stable when wet that won't spew toxic dust into my home?"

I am not a professional and I know of no such product. Like I said before, tearing up what you've already done and starting over with a building system that is poured or formed (like cob) rather than cut will reduce the amount of dust. We haven't evolved to tolerate the presence of particulates in our air so anything that will produce dust when cut will produce respiratory reactions when that dust is breathed in. Including drywall.

You can wear a mask when you visit the job site and hopefully that will help. Honestly I wouldn't too much about this being an on-going issue for you. Once the dust is no longer present in the air you are breathing the reaction should go away.

ETA: I am not suggesting here that cob is a useful tile substrate. I know it is not. My point is that the entire house is going to full of such situations and the only way to avoid it might be to go to a more ancient method of construction that requires no cutting of anything at all, because everything that gets cut will produce irritating dust.

Thanks Lindsey. I'm not worried about the short term (before shower is done.) I'm worried about the long term. Will dust escape continuously into house? Never heard of cob. Will look into that but probably too late. Thanks again.

"Will dust escape continuously into house?"

From cement board? No.

What waterproofing are they using in conjunction with the cement board?

Long term you have absolutely nothing to worry about except whether they waterproof properly or not. And if not, your worry is mold and rot, not dust.

Cob is not an option for you on this house. But it is certainly a fascinating concept and worth the research :)

Dust from Durock? no.

If you're building a shower, it will be sealed (or better be) with a latex-like paint especially made for it. Q: are you allergic to latex? Once it gets sealed up in mastic, tile and grout, it might as well be buried a mile underground.

A house under construction is full of saw dust, fiberglass fibers, gypsum dust, paint fumes, carpet fibers and all sorts of things you could react to.

I too am smelling the odor of Durock. It has a chemical smell like someone use a bad version of pinesol to clean furniture. I just bought some and it is sitting in my living room waiting to be installed. Not a cut done yet. it is a slight odor but to someone with odor sensitivities it could easily cause a headache. I have not previous experience with it but I'm wondering will this odor start to go through the walls and go throughout the house. I'm wondering why can't we just use plywood and waterproof that and then install the tile on top of that.

"I'm wondering why can't we just use plywood and waterproof that and then install the tile on top of that." Not an acceptable substrate for tile in a wet area.

" will this odor start to go through the walls and go throughout the house." No. You considered plywood. Does your home smell like wood now? Considering it may have a few boards in the walls:)

A new car has that new car smell. A new carpet has that new carpet smell. A paper bag, new drapes, Research off gassing.

With that said. The cement board should not be cut indoors with power tools ever.

'I'm wondering why can't we just use plywood and waterproof that and then install the tile on top of that."

Wood is not ever an acceptable substrate for tile because it's dimensionally unstable. It expands - mostly across its grain - as the humidity or moisture level changes. When that happens, it opens up cracks in tile and grout, and the problem goes downhill quickly.

When I was very young I installed a tile countertop in my kitchen over a particle board base.... I got a quick education on why you don't do that.

Do you know if they had just laid some tile in other areas of the bathroom when you visited the house? Tile adhesive, especially floor tile adhesive, has a strong chemical smell that can linger for a day or two. Perhaps that's what you smelled?

Ok... Thank you for all the responses. That is good to know. I'm wondering then should I put a plastic vapor barrier over the studds before installing the Durock board? I have seen some forums where they are fully for it.... and others saying no, you'll create a moisture sandwhich and lock in moisture... which I find strange seeing as that if if found its way in... should it not also find its way out.

Also... because I've had to shim out / furl out some of the 2x4s to get an nice even surface line for the Durock board to sit nicely on... I'm worried that the special screws I have for the Durock board which are 1&5/8 length. They just don't seem to be long enough for me and I can't find any longer. Is it acceptable to use maybe 5-6 8x3 Decks screw to get a bit more depth in certain areas and then continue using the proper screws throughout the rest of the installation. I've heard that other screws will have issues due to the chemicals in the Durock. Any thoughts on that?

I'm confused. Are you doing the work yourself? You said you visited the construction site and had this respiratory problem. Now it sounds like you're actually doing the work.

I'm doing the work myself. I never said I visited the construction site. You must have misread something or interpreted it incorrectly. (its happened to me before)

From the first post:

"Hello Houzz friends, I was visiting our in-construction bathroom today and they have Durock on the shower walls. The irritation was very strong."

Thats not my comment. Its a different user that posted that. The handle that was given to me is HU-312995516 ... the top user that posted that is HU-870157674

catbuilder this is a three year old post and now a new person is piggybacking onto it rather than starting their own.

HU-312995516- start your own post. adding onto an old one is super confusing and in many cases, the original poster is no longer around to answer any new questions.

And while you're at it, give yourself a name, not a random number.

Sorry everyone, I only came across this site looking for answers. I really had no intention to confuse. Wasn't sure how it all worked. I just thought to post my question here.

Plywood should never be used in wet areas. Half inch plywood is ok for a tile substrate on floors although I would use a decoupling membrane with it. I have half inch plywood and Nobelseal TS on my bathroom floor.

In my home, that strong chemical smell was evident after they installed the Durock, it was visibly moist, as in just in from the manufacturer, and not dried out yet. Some weeks passed and it seemed to dry. Tile was installed over a Schluter system, all is intact, looks great, is flawless! NOW THE PROBLEM: The odor coming out of my new bathroom is upsetting. No, its not sewer gas, and the house is spotless. You CAN smell this odor when you enter the home to some degree, and it is worse in the bath and hallway leading to the bedrooms. I smell it in my bedroom and office next to the bathroom, not as strong. All of the surfaces are clean, new hardwood flooring throughout. Every inch of the upstairs, walls were washed three times during my remodel. The hardwood sat for months and offgassed before install. I thought it was backdraft from my bathroom exhaust vent that was not yet vented through the roof, but that was done and nothing changed. I purchased a rather expensive air purifier and... no luck! This is not mold, there is NO mold anywhere. The home has no leaks, I know every nook and cranny in the home, including the underside of the roof and the basement sill plates. I have a CO2 detector which shows zero, no gas range, and this isnt a gas smell. Im struggling with this. I even had all of the ducts and returns cleaned and looked in with the camera after completion, no chemicals used there either. The duct system has a mighty 2" filter. I inquired about having my furnace A coil cleaned and the HVAC person tried to talk me out of it. Says this is not needed; I read otherwise. Also, the smell is evident without the furnace running. I have the same furniture I had in my previous home. Could this smell be the Durock? Could it be the drywall I replaced? It is a sweet smell, the glue used during the flooring install? Suggestions welcome. Thanks in advance.

"Could this smell be the Durock?"

No. Page 4 of 8 "Low to no odor."

"Could it be the drywall I replaced?"

No again.

I'd open all the doors and windows for a day and let it air out. If it's cold where you are, shut 'em just before your pipes freeze and burst. Maybe install a whole-house attic fan.

so it’s a chemical smell not a sewer smell? sometimes P traps in baths can be a culprit

Hey folks, this is a 5 year old post that multiple people glommed on to - some who had contractors and some doing it themselves. It's a mess... let it die and start a new thread if you have questions.