[venik]

This is not REALLY a plumbing question, but the experts here might be able to help. My tile man has installed "waterproof" sheetrock (green) on the walls that he is about to tile in a renovated bathroom. I heard that for a bathroom, one should use WonderBoard instead, because of its superior water resistance. Is sheetrock OK under tiles in a bathroom, including in the tub enclosure?
Thanks a lot--

[RickJ]

Don't sweat it. The green sheetrock is just fine - assuming the tile will be done right, then the grout sealed and the caulk job done right.

If you were considering wonderboard before they started... and the price difference was something you could live with, I'd say go ahead... but the truth is, the green sheetrock is still the standard.

[venik]

Thanks, but in the meantime I have discovered that the manufacturer of the GreenBoard do not recommend using this MR (Moisture Resistant) board for tub and shower enclosures, and instead recommends using cement based board, like PermaBase. Your reassuring response was the only positive comment I found.

[RickJ]

I'm not too surprised to hear this. That is the case with a lot of builder supplies.

Lauan is another example. The manufacturer does not recommend using it as a subfloor for many materials, yet it remains the #1 builder choice for a subfloor.

If your tile guy is reputable, ask him what his suppliers say about this. And to be sure make 2-3 calls to other contractors.

If speedball1 does not come along shortly, PM him. He is a retired construction forman and plumbing expert. I count on his expertise as gospel.

[RickJ]

PS/Clarification.

I'm not "defending" the sheetrock, just sharing my experience. :o

Truth is, if speedball1 says to use wonderboard - or a similar product - I, also, will heed it and start using it... even though I've been using green sheetrock for years and really haven't run into problems...

[venik]

Further research taught me that greenboard will be outlawed as a base for tiles in tubs/shower after 1/1/2006. Glad we caught it before the tiles were cemented to the sheetrock.
Thanks for all your help!

[speedball1]

Sorry guys!
The plumbers are out of there by the time the drywall and tile dudes come in.
They follow us in when we get inspection in the "tub-set and waterpipe" stage and then we follow them when they're done for the trim out stage. Cheers, Tom

[RickJ]

Good eye, venik. I had no clue.

I wonder, though, what the issue is that would make it actually illegal. Is there some hazmat issue with it or something?

I wonder too why your tile guy did not know this.

I'm going to have our maintenance guys dig into this issue further. If I run into anything that clarifies it, I'll post it here.

I hope your tile guy will credit you for the green stuff and remove it at no charge ;)

[venik]

He grumbled and complained, but he did remove the stuff, seeing that as of Jan. 1, 2006, it will be anlawful to use it in tubs and showers. This certainly has been educational!

[wait108]

I have it on good authority that water-resistant sheetrock is fine for the walls, and the floor should be Wonderboard, depending on if you're using roll-out tile or grouted stone tile... since it resists decay. But pricey...

[DonBeers]

"Green board", as us old dogs called it, has worked well for years, like he said; if the tile is properly installed and SEALED adequately, the tub surround should not fail. I'm not saying anything new here; just agreeing with Ricks' initial response. I like to think that my 24 years experience along with his reply will put you at ease during your remodel.

[_Homer]

I've used both sheet roc and green rock under tile walls with mixed results. Some lasted 15 to 20 years, others needed re grouting or tile replacement.
The biggest cause of the failure was not the tile work or finishing but the poor construction of the tub or shower area where the walls would move or settle, this lets moisture in and adhesive failure begins.

Beed doing this over 40 years, getting ready to do two showers within the month with shower bases.

I'll use the kerdi waterproof mat on the walls, then tile. I'd use the wonder board or dura rock on the floor then membrane over it, my approach. Anchor the wall boards well whichever you use. Homer G.

[Milo Dolezal]

I have seen it done both ways: with green-board and with cement board. Both ways is OK. However, when tiling our own new shower - we used 1/2" Durarock board.