Installing a beautiful tile backsplash can instantly upgrade the look of your kitchen or bathroom. However, ensuring that your backsplash installation is done properly is key to achieving the best results. One important consideration is whether you need to install backer board prior to tiling. Here is an in-depth look at whether tile backsplash requires backer board.
What is Backer Board?
Backer board, also known as cement board, is a sheet material used as a tile underlayment for walls and countertops. It is made from portland cement sandwiched between fibrous mats.
Backer board is designed to provide a stable, water-resistant surface for tile installation. It is an alternative to using drywall as a tile substrate. Backer board is much more durable and moisture-resistant than regular drywall.
Some key advantages of using backer board include:
- Prevents mold and mildew growth – Backer board resists moisture penetration, preventing mold and mildew growth behind tiles.
- Highly durable – It won’t easily crack, warp or deteriorate over time. This provides a stable surface for tiles.
- Fire resistant – Cement board is non-combustible and fire resistant.
- Works well with thinset – Thinset mortar bonds very well to the surface of backer board.
When is Backer Board Required for Tile Installation?
Backer board is required as an underlayment for tile installation in the following locations:
Tile Backsplashes
Backer board is recommended for tile backsplashes in kitchens and bathrooms. The main reason it is advised for backsplashes is because this area is prone to moisture exposure from cooking, cleaning and steam from showers.
Backer board prevents moisture from saturating the drywall behind the tile and causing deterioration or mold growth. The durable surface also provides stability for a long-lasting installation.
However, backer board is not always required for backsplashes according to building codes. Some exceptions are:
- Low-moisture environments – Backsplashes away from sinks/stoves may allow regular drywall.
- Small superficial backsplashes – Small 4-6 inch backsplashes may not require backer board.
- Painted backsplashes – If tiling over painted drywall, backer board may not be needed.
For best results and maximum durability, backer board is highly recommended for kitchen and bathroom backsplashes. But it ultimately depends on the extent of the backsplash and the amount of moisture exposure.
Shower and Bathtub Surrounds
Backer board is required by code for shower enclosures and bathtub surrounds. These areas experience heavy moisture and require a water-resistant substrate. Drywall should never be used behind tile in showers or bathtub surrounds.
Floors
Backer board is sometimes used on floors as an underlayment for tile installations. Cement-based backer board provides a very stable surface for floor tiles.
However, more often a cementitious self-leveling underlayment or concrete board is used on floors prior to tiling. Backer board is not as rigid for flooring applications unless installed over plywood or OSB subfloor.
Countertops
Backer board can be used when tiling over a countertop as an alternative to plywood. It provides a smooth, durable surface and resists moisture well. Backer board is commonly used for concrete countertop forms before pouring concrete.
Advantages of Using Backer Board for Tile Backsplashes
Although backer board may not be an absolute requirement for tiles backsplashes, there are some great benefits to using it:
- Prevents cracks – Backer board provides a more stable substrate, preventing cracks from transferring through the tile.
- Long-lasting – Backer board stands up well to moisture and everyday use without deteriorating.
- Mold resistant – The water-resistant surface prevents moisture from seeping through to the drywall and causing mold.
- Versatile installation – Backer board can be installed directly over existing surfaces like drywall or plaster.
- Thinset bonds well – Thinset mortar has excellent adhesion to the porous surface.
Backer board does add more in material costs than just using drywall. But the advantages for backsplashes make it worth considering.
How to Install Backer Board for Tile Backsplashes
Installing backer board for a backsplash is relatively straightforward. Here are the basic steps:
Step 1: Prepare the Surface
Start by making sure the wall is flat, clean, and free of any oil or debris that could prevent adhesion. Sand off any glossy paint coats or wallpaper adhesive.
Fill any large gaps or imperfections with joint compound to flatten the surface. It’s important the wall is as smooth as possible before installing backer board.
Step 2: Cut the Backer Board to Size
Measure the backsplash area and cut the backer board to size with a utility knife or backer board shears. Be sure to account for outlets and other obstructions. Cut holes for electrical boxes using a drywall saw.
Cut boards 1/4 inch smaller than the vertical height to account for thinset thickness. You may need multiple boards for wide backsplash areas.
Step 3: Fasten the Backer Board
Apply thinset mortar to the back of the backer board using a 1/4 inch square notched trowel. Then firmly press the backer board to the wall.
Fasten the backer board using backer board screws every 8 inches across the surface, making sure all seams are supported. Orient the boards so seams don’t align with cutouts.
Step 4: Tape and Mud the Seams
Mix up some thinset mortar and apply it over all seams and corners, embedding alkali-resistant fiberglass mesh tape.
Smooth and level all the seam areas. Allow the thinset to fully cure before applying any waterproofing or beginning to tile.
Once the backer board is installed and prepped, you can begin tiling! Be sure to use a polymer-modified thinset suitable for cement board when setting the tiles.
Conclusion
Installing backer board is the best practice for many tile backsplash installations. Although it may not be an absolute requirement in all cases, it provides a moisture-resistant, stable surface that can prevent cracks and help your backsplash last.
While backer board does add more in material costs, the advantages it provides are often worth the investment for a professional quality result. With the right tools and techniques, installing backer board is a straightforward process before tiling.
FAQ About Backer Board for Tile Backsplashes
Does all tile backsplash need backer board?
No, backer board is not an absolute requirement according to building codes, but it is highly recommended for kitchen and bathroom backsplashes. Backer board provides extra moisture protection and stability.
Can you put tile backsplash directly on drywall?
Tile can be installed directly on drywall in some cases, such as for painted backsplashes or very small superficial backsplashes. For best results, backer board is advised for most tile backsplash installations.
What can I use instead of backer board?
Fiber-cement, fiberglass-mat, or glass-mat backer boards can be used as alternatives to traditional cement backer boards. Some acrylic-coated or vinyl backer boards are designed as a replacement for cement board as well.
Can you put backer board over existing tile?
In some cases it may be possible to install new backer board over existing backsplash tile. The old tile surface must be well bonded, properly prepared, and high quality thinset should be used to adhere the new backer board.
How thick should backer board be for backsplash?
A 1/2-inch or 5/8-inch cement backer board is typically recommended for backsplashes. Thicker 3/4-inch backer board may be advised for floor installations but is not necessary for walls.
Key Takeaways
- Backer board provides a water-resistant, durable surface for tile backsplashes. It prevents deterioration and mold growth.
- Backer board is highly recommended for kitchen and bathroom backsplash installations but may not be an absolute requirement.
- Shower surrounds do require backer board according to code. Backsplashes are a recommended best practice.
- Advantages include preventing cracks, durability, mold resistance, and versatility.
- Installing backer board involves preparing the surface, cutting boards to size, fastening to the wall, and taping the seams.