What wall board surface under tile in shower?

[Chris_G]

My G.C. has put up walls in the bathtub/shower that are meant to be tiled over. I want to make sure this is the correct surface. It is not a shower stall, but a bathtub with tile walls.

Two of the walls are wood stud walls with fiberglass insulation in between, and the longer wall behind the tub is a brick wall. It is an old building, and the brick wall is slightly out of level, so the carpenter put up 2x2" metal studs to level that wall, then fastened the sheet-rocked onto the metal studs.

The carpenter has put up a light green board that is labeled:

SHEETROCK (R) Brand W/R FIRECODE (R) TYPE X GYPSUM PANEL

Is this a proper and sufficient surface to apply tile to in a bath/shower area?


What should be done to a wall in a bathroom in order to properly prepare it for receiving tile?


Thank you for any advice.
-chris

[jadnashua]

In a shower area, cement board (cbu) is now the national code (may not be adopted locally, though). Greenboard used to be acceptable, but was not a great choice.

You've got several choices - remove both and install cbu, or leave what is there and cover with a waterproof membrane such as Kerdi from www.schluter.com. Pay particular attension to the edge by the rim of the tub...if the drywall touches the tub, it will swell and fail plus it will degrade with mold.

For guidance on tiling questions, suggest www.johnbridge.com.

[Chris_G]

Thanks, jadnashua. That is very helpful.

I read somewhere, either on this forum, or on another of this nature, about a similar product to Kerdi, but the membrane is painted on, rather than applied in a sheet. Does anybody have any experience with this? If so, did it achieve comparable results, or not?

I'm going to look into this again and see if I can find that information.

Thank you again.

[jadnashua]

Redgard by Custom Building Products is one, there are others. Latticrete makes a nice system, to. Redgard is available at HD and tile stores for about $40/gallon.