Do you put backer board over tub flange?

ANSWER – No there should not be a gap between the top of the bathtub flange and the backer board on the wall. The backer board should overlap the tub flange so the tile has a stable backing to attach to. This requires shimming the backer board out from the studs so the wall is plumb.

What do you do with a gap between tub and cement board?

Caulk the gap Ideally, you would leave a 1/8 inch gap which would then have the sealant applied to it. Either stopping the cement board above the tub flange or alternately shimming it out and dropping it down near the tub would both be good options.

Can I use silicone on cement board?

Cement board is to be screwed down and used with thinset. As for the marble you are installing you’ll need a waterproof adhesive,not silicone. You may use a 100% silicone on the joints for expansion control.

Do you need to put a vapor barrier behind cement board?

Their online instructions/diagrams show no use of a vapor barrier. You should, so that any moisture that gets behind the cement board runs into the tub or shower instead of into your wall cavity (causing rot or mold/mildew).

Should cement board go over tub lip?

The best approach when installing cement board or other tile backer around a tub is to keep the cement board out of the lip area. Apply it to the wall with the bottom edge about 1/4 in. above the lip of the tub. Fill the gap between the tile and the tub with caulk.

How do you fix a gap between tub and tile?

If you have tile on the wall adjoining the tub, select a caulk that matches the color of the grout. If your gap is smaller than 1/8 inch in width, use regular caulk; fill gaps larger than 1/8 inch with a sanded caulk. Make sure the gap is clean and dry, then squeeze a thin, even bead of caulk into the space.

Where should cement board sit on tub flange?

The best approach when installing cement board or other tile backer around a tub is to keep the cement board out of the lip area. Apply it to the wall with the bottom edge about 1/4 in. above the lip of the tub. Then apply a generous amount of thin-set to the bottom bathtub tile and position it 1/8 in.

Does 100% silicone stick to Redgard?

Caulk that gap with siliconized or latex caulk and then use Redgard over the caulk. Regard will not stick to 100% silicone caulk. You DO NOT want moisture collecting in that crevice and it can if you stuff it with thinset.

How do you put backer board around a tub?

Apply it to the wall with the bottom edge about 1/4 in. above the lip of the tub. Then apply a generous amount of thin-set to the bottom bathtub tile and position it 1/8 in. above the tub. Fill the gap between the tile and the tub with caulk. What is Backer Board?

Is the tub flange sealed to the backerboard?

The tub flange is sealed to backerboard That pesky tub flange. You have the tile backerboard installed and everything is waterproofed. Everything except that gap between the backerboard and the tub flange. How do you waterproof that? What to do with the tub flange?

What do you do with the tub flange?

Pin That pesky tub flange. You have the tile backer board installed and everything is waterproofed. Everything except that gap between the backer board and the tub flange. How do you waterproof that? What to do with the tub flange?

Is there supposed to be a backer board gap above a bathtub?

So the backer board and the vapor barrier behind it should overlap the flange leaving no more than a 1/4″ gap, but no less than a 1/8″ gap, above the bathtub ledge. That joint should be filled with a foam backer rod and an ASTM C920 sealant.