Installing a tile backsplash can transform the look of your kitchen or bathroom. While tiles add style and visual interest, installing them properly ensures they stay securely in place for years to come. A critical step when tiling over drywall is to first install backer board. Also called cement board, backer board creates a water-resistant, stable surface for tile adhesion.
Learning how to install backer board for a tile backsplash correctly is important for success. With the right materials and proper technique, you can create the perfect base for a stylish and durable tiled backsplash.
What is Backer Board?
Backer board, also known by the brand name Hardibacker, is a cement-based board made of Portland cement and sand reinforced with fiberglass mesh. It is water-resistant and designed not to warp, bend or sag when exposed to moisture over time.
Unlike drywall, backer board will not degrade or disintegrate when exposed to prolonged dampness. This makes it an ideal substrate for wet areas like behind sinks, around bathtubs and for tile backsplashes prone to water exposure from cooking, cleaning or splashing.
When installed correctly, backer board provides a durable, smooth and moisture-resistant surface for superior tile adhesion.
Benefits of Using Backer Board
There are several important benefits to using backer board instead of drywall when installing a tile backsplash:
- Prevents mold and mildew: Backer board is waterproof and mold-resistant, preventing mold, mildew and moisture damage.
- Superior tile adhesion: The cement surface provides excellent adhesion for tile mortar. Tile installed over backer board is less prone to cracking or loosening over time.
- Adds strength: Backer board is very rigid and does not sag or warp when exposed to moisture. This provides a strong base for tile.
- Fire resistance: Backer board is non-combustible and fire resistant.
- Long-lasting: Properly installed backer board can last for the lifetime of the tile, providing a permanent substrate.
Tools and Materials Needed
Installing backer board is a relatively straightforward DIY project but does require some specific tools and materials:
- Safety glasses and gloves
- Tape measure
- Utility knife
- Backer board screws
- Power drill and screwdriver bit
- Cement board saw or utility knife
- Backer board (Hardibacker or equivalent)
- Thin-set mortar
- Fiberglass mesh tape
- Construction adhesive (Liquid Nails)
- Screws for cement board
Step-by-Step Installation Guide
Follow these key steps to properly install backer board for a tile backsplash:
Step 1: Measure and Cut the Backer Board
- Measure the area where the backsplash will be installed.
- Cut the backer board to size using a cement board saw or score and snap utility knife.
- Cut pieces to fit your pattern – full sheets, halves, etc.
Step 2: Apply Thin-Set Mortar
- Mix thin-set mortar according to package directions.
- Apply a layer of thin-set mortar to the area where the backer board will be installed using a 1/4” notch trowel.
Step 3: Apply Construction Adhesive
- Run a continuous bead of construction adhesive along the wall studs where the backer board will be attached.
Step 4: Install the Backer Board
- Place the first sheet firmly against the wall and press into the mortar and adhesive.
- Use a level to ensure the board is plumb.
- Use screws designed for cement board to attach the board every 8 inches along studs and edges.
- Install remaining sheets in the same manner, maintaining 1/8” gaps between boards.
Step 5: Tape the Seams
- Place fiberglass mesh tape over all seams between backer board sheets.
- Apply a layer of thin-set mortar over the tape using a trowel.
- Feather out the mortar 2-3 inches beyond the tape edges.
Step 6: Allow to Cure
- Allow the thin-set mortar to fully cure for 24-48 hours.
- Inspect for any gaps needing additional mortar.
- Scrape off any high spots or excess mortar.
The backer board is now ready for tile to be applied! Be sure to use a compatible mortar approved for cement board when setting the tile.
Tips for Successful Installation
- Stagger the backer board seams similarly to drywall sheets.
- Pre-cut outlet holes for electrical boxes and plumbing fixtures.
- Use backer board screws designed for cement board – they have sharp points and wide threads.
- Hold sheets off the countertop by 1/8” to allow expansion space.
- Avoid putting seams where the tile seams will be. Offset them.
- Use sanded caulk to fill any gaps before applying tile.
Installing backer board properly takes a bit more time and effort than drywall but provides a permanent, moisture-resistant surface for tile. With the right preparation, you can feel confident your backsplash tile will maintain its integrity for many years to come.
Frequently Asked Questions
What thickness of backer board should I use?
For wall applications like backsplashes, use 1/2″ thickness. It provides sufficient rigidity without being overly heavy.
Should backer board seams be taped?
Yes, taping the seams with fiberglass mesh reinforces them and prevents movement or cracking between the boards.
Can I use drywall behind a backsplash instead?
Drywall is not recommended as it can warp and degrade over time when exposed to moisture. Backer board is designed specifically for wet areas.
What kind of thinset mortar should I use?
Use a polymer-modified mortar designed for use with cement board. Do not use organic mastic or plain thinset.
Can I use galvanized or drywall screws?
No. Use corrosion-resistant backer board screws which have sharp points and wide threads. Others may break or corrode over time.
Installing backer board is a crucial first step for a long-lasting, trouble-free tile backsplash. While it requires careful cutting, screwing and taping, the extra effort provides a waterproof surface designed for the demands of wet areas like kitchens. Be sure to use the manufacturer’s recommended products and allow proper drying time. With the right prep work, you can install an beautiful backsplash that will hold up beautifully over time.