Waterproof tile backing board is only necessary for walls and floors that will be directly exposed to running water, such as in a shower. A backer board is not required for all wall tile. For instance, a tile backsplash in your kitchen can be installed over standard drywall. This is because the wall tile in your kitchen is exposed to minimal moisture compared to shower walls.
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When Should You Use Backer Board?
You need to install backer board wherever you will be installing interior tile that will receive direct exposure to water. This includes shower floors and walls. It also includes any exterior walls with tilework or tile accents.
- Use a specialized waterproof backer board wherever tile will be exposed directly to water or rain.
- Shower floors and walls must be backed with a waterproof backer board to prevent water damage to your home.
- Exterior walls with tile must have a waterproof backer.
- A waterproof backer board is not required for kitchen and bathroom backsplashes.
If your tile will not be directly exposed to a spray of water, a specialized backer board isn’t required. Because backsplashes and tile walls in your kitchen are exposed to minimal water, you can install tile on drywall. In bathrooms, use water-resistant drywall for all non-shower areas. You can install a bathroom backsplash onto this water-resistant drywall. There is no need for a cement backer board in these areas.
Does Your Shower Wall Tile Need Backer Board?
It is essential to install a waterproof backing board before tiling shower walls. Drywall is not an acceptable surface for tiled shower walls. When exposed to water, even after it has been tiled, drywall will absorb moisture. This leads to mold, rotted wall studs, and a deteriorating wall that can cause tile to come loose. Moisture-resistant drywall, sometimes called greenboard, is not an acceptable substitute for a true backer board.
- Shower walls must be backed with a waterproof backing board.
- Drywall is not an acceptable backer board. Even moisture-resistant drywall (green or blue varieties) will not hold up in showers.
- Use a true cement backer board, or try a shower backer board kit like this one.
Use a waterproof backer board designed for tiled shower walls. Cement board is the traditional backer board for tile installations, but several brands make excellent waterproof backer boards for showers. These brands include Kerdi Board, HardieBacker, and Wedi Board.
Does Backer Board Go Over Drywall?
Never install tile backer boards over existing drywall. This will lead to trapped moisture and waterlogged drywall, which can still contribute to mold, mildew, and decay in your home. Before installing backer board remove all existing drywall and wall material. You must strip the wall down to the studs, then install your waterproof backer board directly onto the wall studs.
- Do not install backer board over drywall.
- Remove all drywall and strip the wall to the studs before installing backer board.
Odds are, only a portion of your room will be backed with backer board. If you are using cement board, follow our tips to seal joints between backer board and drywall.
Can You Tile Directly on Drywall?
It is perfectly acceptable to tile on drywall in any area that isn’t directly exposed to running or spraying water. For instance, kitchen backsplashes, bathroom backsplashes, around fireplaces, and accent tiles in interior decor can be installed directly on drywall.
- If the surface will not be exposed to direct water spray, you can tile on drywall.
- Tile over drywall for your backsplashes, wall accent tiles, and fireplace surrounds.
- Use backer board for shower walls and floors.
In most homes, the only place where backer board is required is in the shower. It is one of the few places in your home that is sprayed directly with water. The amount of water that comes in contact with a backsplash is minimal compared to your shower walls.
Do You Have to Use Cement Board Behind Tile?
It’s imperative to use a cement board or another waterproof backing board behind the tile in your shower. In most other applications, including in kitchens, you can tile directly onto drywall. Do not attempt to cut corners by tiling on top of drywall in your shower. Both standard and moisture-resistant varieties of drywall will begin to mildew and break down if used in your shower. If this happens, your home can be invaded by mold and your tile job may fall apart as the drywall behind it crumbles.