Home>Discussions>BATHROOMS>Drywall over tub flange
14 posts / 0 new
Last post
JLMCDANIEL
Re: Drywall over tub flange

Sombreuil_mongrel I am not criticizing the information you provided, or your well founded concern. Just a reminder that you are dealing with DIYers, many times first time posters, that may not be familiar with tiling nomenclature and to harsh a stand sometimes scare posters away. It is sometimes very difficult to draw a line and tell someone they need professional help when they have sat and watched how easy every thing is on TV. Just be gentle, it may be their first time.:D

Jack

Timothy Miller
Re: Drywall over tub flange
Sombreuil_mongrel wrote:

Are we talking about a tub without an integral surround? Just a tub, right?
So drywall down to the tub flange is not the greatest idea; the only product to make that situation have any possibility of success is Kerdi membrane to waterproof it, but even then it's better to use a wallboard that will not break down when wet, like Durock cement board.
Now, another snag, you said mastic, I heard you so don't deny it! Mastic is a very very bad thing for tub surrounds and showers. You will be doing the job over again very shortly, because all the tiles are guaranteed to fall off if you use mastic (or premixed thinset, for it is mastic + sand). You must, must, must use the proper thinset, determinant upon what kind of substrate and what type of tile you are working with. Thinset is made in many formulations from unmodified, which is just portland cement plus very fine sand, and the variations are created by adding various acrylic or other resins to the mix either in the dry mix or as a liquid additive. The more highly-modified, the longer it takes for them to set; plain portland will set without the presence of air, because it is a pure chemical reaction. Modified thinsets however DO require air, and if applied over a membrane or impermeable material (Redguard, etc) they would require months to harden. Stone tiles demand an unmodified thinset to avoid the bleeding out of the resin to the stone, which causes a permanent stain. White marble has to be laid in white thinset for a similar reason; a grey mortar would reflect through the white tile, resulting in an unsightly condition.
Similarly, white mortars are called for under most transparent glass tiles that are not lined.
You must get some straight answers and good free advice from your tile supplier as to what materials are appropriate for the job.
S_M

Hi S M. AAA+ you are the Man.

A. Spruce
Re: Drywall over tub flange
JLMCDANIEL wrote:

It is sometimes very difficult to draw a line and tell someone they need professional help when they have sat and watched how easy every thing is on TV. Just be gentle, it may be their first time.:D

Jack

Stay in this business long enough and we ALL need a little professional help! :eek:;):p:D

Pages

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.