Does cement board go over lip of shower pan?

ANSWER. ANSWER – No there should not be a gap between the top of the bathtub flange and the backer board on the wall. The asphalt paper or polyethylene should overlap the tub flange so moisture that collects on the moisture barrier can evacuate into the tub; or more important so it can’t get into the wall cavity.

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.

Secondly, can you tile directly on cement board? Cement board is used for most floor tile and has all but replaced plywood and drywall backer materials for wall-tile applications in wet areas, like showers and tub surrounds. Ceramic tile laid over cement board is one of the most durable floor or wall surfaces you can install.

Beside above, do you put cement board under a shower pan?

Should the shower pan be set in mortar anyway (even if I level the cement board subfloor)? You don’t really need cement board under the pan, but you do need a level solid surface. Leveling cement would be all that is needed, but should be thicker than 1/2″.

Does it matter which side of cement board faces out?

Cement board has a smooth side and a rough side. Face the rough side out if you will be using thin-set mortar adhesive to install the tile but the smooth side out if you will be using latex mastic.

Do you have to tape cement board before tiling?

2 Answers. The thinset and mesh tape are to strengthen the seams. If you are going to tile over the cement board, you should tape the seams. If you just want to leave the corners untreated that will probably be fine, because that seam won’t split the center of a tile.

How do you fill 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.

Do you need a vapor barrier behind cement board?

You still need a vapor barrier with cement board, although in this case the barrier can go behind the board. Cement board is heavy enough and breathable enough to take the moisture without a problem. By having the vapor barrier behind the cement board you stop the moisture going further into the wall.

How much space should be between cement board and tub?

There should be a 1/4″ gap between the tub ledge and the backer board. Technically, after the tile is installed over the backer board that gap between it and the tub ledge should be filled with an ASTM C920 sealant (caulking e.g. silicone).

Does subfloor go under bathtub?

Flooring repairs can be intimidating, but the subfloor under the tub generally consists of plywood secured over floor joists and is fairly simple to replace — once you get access to it. The entire tub unit requires removal before subfloor replacement can begin.

Can I use deck screws for cement board?

There are screws made for concrete board. Bugle head like drywall screws but they are coated to resist corrosion and have sufficient strength to support the board. The heads are larger than deck screws or drywall screws, too. Rona, HD, HH will all have them.

Do I need to waterproof shower walls before tiling?

Prepping for shower tile is different than the prepping for tile on drywall. A shower is considered a wet application, so you need to waterproof the foundation, which you’ll learn how to do in these instructions. After the waterproofing step, the instructions are the same as if you were installing tile on drywall.

Do you need to waterproof cement board in a shower?

Cement Board and a Sheet Membrane After the thinset has dried, tile is applied to the sheet membrane with thinset. Kerdi can also be installed directly over standard drywall in a shower because, when installed correctly, it creates a continuous waterproof barrier.

Can I use 1/4 cement board on floors?

Floors. Both 1/4- and1/2-inch cement board are appropriate for floors. To install cement board on floors, cement board manufacturers mandate a 5/8-inch plywood subfloor or OSB underlayment. They also require a 3/4-inch subfloor where tile size exceeds 12 inches.