Hi all, have a question for the tilesetters out here. I’ve got a job setting ceramic 12×12 tile for a customer. The bathroom is in a 2nd floor condo of a multiunit building. The current subfloor is 3/4″ OSB followed by 3/4″ of gypsum that was poured over the OSB. Question I have, is this enough of a base to lay the tiles directly on or should I still plan on laying some Durock or other cement board on top of this? If so, what thickness board should I use, 1/2″? Also, how do I attach the durock to the existing floor? Glue, nails, screws, or a combination? Last, customer wants to put in marble diamonds in the corners where every 4 tiles meet. What is the best way to set these marble tiles? With a thinset mortar low in sand or????
thanks!
Replies
The gypsun is not a very good setting bed for wet applications. I would be inclined to remove it, or membrane it. If it gets wet, it will turn into mush. I would probably use a PVC membrane like NobleTS, then tile.
Just install the membrane using thinset and let set, then thinset your tiles onto the membraned gyp.
Your 12x12 tiles will call for a fairly flat surface. Check it with a 6 foot level before doing anything and use Custom's QuickFix to patch and fill in holes in the setting bed.
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
I would shy away from that job unless the substrate would be replaced. We had to demo an entire apartment complex worth of gypcrete floor. It was so easily demoed, and wasn't attached at all to the decking.
rg