Can you install Kerdi membrane over drywall?
Yes. Once you install KERDI over the drywall panels, they will be completely protected from the water and vapor in your tiled shower.
Can you put Kerdi membrane over cement board?
5 Answers. First Kerdi can be installed on drywall or cement board. However if installed on drywall it is only protecting one side. The back side of the drywall fails and it is just as bad or worse than if it had an issue on the tile side.
Can you put Kerdi membrane on floor?
If your bathroom floor is a concrete slab, you could use Kerdi. Kerdi is a waterproofing membrane, so you can use it on any surface that is already suitable for tile.
Do I need a vapor barrier behind Kerdi?
Kerdi is the vapor barrier, there is no need for anything behind it. Kerdi can even be installed over drywall. Cement board and grout are not water proof, if there’s Kerdi no moisture is ever going to be able to get behind it.
Does Thinset stick to RedGard?
You”ll be fine with thinset over Redguard on walls. It’s recommended for waterproofing niches, shelves, and entire shower walls when tar paper or poly are not used as a vapor barrier behind the CBU.
Should cement board overlap the tub?
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.
Which side of the cement board goes out?
Screw the board in place
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 need 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).
What do you put behind cement board in shower?
Use an appropriate waterproof or moisture-resistant backing material behind grouted tile or stone or segmented plastic or fiberglass tub and shower surrounds. Appropriate materials include cement board which has a cementitious core and glass mats on both sides to strengthen the board.
Can you use cement board in a shower?
Cement board can be used just as effectively on walls, such as showers and bathtub surrounds, as it is on floors. Doing this will require that you remove the existing surface material before installing backerboard over the studs.
Can you use drywall screws for cement board?
You don’t want to use regular drywall screws for cement boards. They can corrode, they can break down the edges of the boards, and they won’t drive in flush properly. Use ITW’s ROCK-ON and BACKER-ON screws instead.
Does cement board need to be waterproofed?
So, if you’re looking for durability and strength, concrete backer–board will probably be your choice. First, you should provide a waterproof/resistant membrane against the wood studs before installing the concrete backer–board to protect the wood studs from moisture absorbed through the backer–board.
Do I need to seal cement board before tiling?
Contrary to popular thought, tile and grout are not waterproof, and some moisture will penetrate even if sealant is used. However, if you choose to use concrete backerboard, which is much stronger and more durable than gypsum board, a water vapor membrane must be placed underneath it or a sealant applied on top of it.
Which is better cement board or Hardibacker?
HardieBacker is much more light, and it is also the best selling brand of cement board available. It is much cleaner because it does not have any glass in it. It allows for a smooth job with minimal mess. As a bonus, HardieBacker board has an EZ Grid pattern so you can cut perfect lines.
Is cement board stronger than plywood?
Yes,the cement board is stronger than plywood. The cement board is normally used in external areas exposed to environmental exposures.
Do you put plywood under cement board?
The Surface Below the Cement Board
Flooring: For ceramic tile floors, the cement board usually rests on a plywood subfloor (minimum 5/8-inch-thick exterior-grade plywood or OSB). Instead, first, remove the existing surface material, then install the cement board over the studs and membrane, as applicable.
Can you use cement board as a subfloor instead of plywood?
If you‘re working over a wood subfloor, cement board is the right choice for your tile base. No matter what you‘re told at a home center, it’s not a good idea to install tile directly over plywood, especially in a damp area like a bathroom.
Can I use cement board as a subfloor?
Installing HardieBacker Cement Board to a wooden subfloor is as simple as that! HardieBacker Cement Board can be used with nearly any kind of tile, whether ceramic, porcelain, or natural stone. Here’s how to add your tile over your HardieBacker Cement Board: 1.
How do you attach cement board to floor?
What do you attach cement board with?
In general, 1 1/2-inch galvanized nails will hold the board firmly in place. For flooring or wall installation, some builders choose to apply a thin layer of thinset mortar under the cement board to prevent any shifting or expansion. Even if you use this extra adhesive, you should still apply the nails or screws.
Leave a Comment