Installing a tile backsplash can be a great way to update the look of your kitchen. But what if your kitchen already has a granite backsplash installed? Can you tile right over the existing granite?
The short answer is yes, it is possible to tile over granite. However, there are some important factors to consider before taking on this project. Properly preparing the existing granite surface and using the right installation techniques will help ensure your new tiled backsplash lasts for years to come.
Pros and Cons of Tiling Over Granite
There are several potential pros and cons to keep in mind if you’re considering tiling over an existing granite backsplash:
- Cost savings – Tiling over the granite allows you to avoid the expense of removing and disposing of the existing backsplash.
- Preserves countertops – Removing a granite backsplash risks damaging the adjoining countertops or back wall. Tiling over avoids this risk.
- Quick project – Prepping and tiling can often be done over a weekend. No need for lengthy granite removal.
- Familiar location – The new backsplash can be installed in the same spot with minimal layout changes.
- Heavier weight – Tile adds weight, so the wall must be sturdy enough to support tiles plus granite.
- Smooth surface – Granite is very smooth, making proper tile adhesion more difficult. Proper prep is critical.
- Height difference – Existing splashes may be thinner than new tile, creating a height transition on the countertop.
- Permanent installation – Once tiled over, the granite will be covered forever and can’t easily be uncovered later.
Carefully weighing the pros and cons will help you decide if tiling over your existing granite backsplash is the right choice for your kitchen.
Preparing Granite Surface for New Tiles
Proper preparation of the existing granite surface is crucial for ensuring your new backsplash tiles adhere properly and stay in place. Here are the key steps:
- Clean thoroughly – Use a degreasing cleaner to remove all dirt, oil and soap residue from the granite. Rinse well and let fully dry.
- Rough up surface – Use 120-150 grit sandpaper to scuff up the entire surface area where tiles will be applied. This promotes better adhesion.
- Apply bonding agent – Brush on a thin layer of bonding agent specifically made for granite. This provides an optimal bonding surface for the thinset mortar.
- Protect countertops – Cover adjoining countertops with painters tape and a plastic or cardboard barrier. This prevents thinset drips from hardening on countertops.
Proper prep prevents tiles from eventually popping off the surface over time. It may add some time upfront, but prevents much bigger headaches down the road.
Selecting the Right Tile and Thinset Mortar
Choosing compatible tiles and mortar are also key to successful granite tiling:
- Ceramic and porcelain tiles are most common options due to their durability and water-resistance.
- Natural stone tiles can also be used as an alternative if the look is preferred.
- Smaller tiles sizes (1 inch mosaic tiles or 4 inch subway tile) are easier to adhere than larger tiles.
- Use a polymer-modified thinset specifically made for heavy tile installations and tiling on smooth surfaces like granite.
- These thinsets have additives (like latex) that make them much stronger and more flexible.
- Allow the mortar to sit for 5-10 minutes after applying before setting tile. This allows it to become a bit tacky, improving adhesion.
- Use a 1/4 inch square-notched trowel to evenly comb mortar onto the backsplash area before applying tiles.
The right combination of tiles, thinset and proper trowel application will help the installation adhere tightly.
Step-by-Step Tiling Installation Process
Once the granite is prepped and materials are ready, follow these best practices for the installation process:
- Apply thinset mortar – Use the notched trowel to evenly spread the mortar onto the lower 2/3 of the backsplash area. Apply only as much as you can tile over within 10-15 minutes.
- Cut tiles – Measure and cut any specialty edge or corner tiles that may be needed. Use a wet tile saw for best results.
- Press tiles into thinset – Starting at the bottom, press tiles firmly into the mortar and push back and forth slightly to “collapse” the grooves and help adhesion.
- Check alignment – Ensure the tiles are level and aligned. Use spacers between tiles to maintain even grout lines.
- Let mortar cure – Allow thinset to fully cure for at least 24 hours before grouting. This prevents tiles from shifting.
- Grout installation – Mix grout according to package directions. Apply grout with rubber trowel, cleaning excess from tile faces with a damp sponge.
- Seal grout – Once grout has cured, apply a penetrating grout sealer. This prevents staining and damage from moisture over time.
With careful prep work, quality materials, and proper technique, your new tile backsplash will look amazing and provide years of lasting beauty over your existing granite.
Tiling Near the Sink and Avoiding Water Damage
The area around the kitchen sink receives a lot of exposure to moisture. Special care must be taken when tiling near sinks to prevent water damage. Here are some best practices:
- Use a 100% silicone caulk between the backsplash tiles and the countertop or sink rim. This prevents water from seeping underneath and behind tiles.
- Similarly, apply silicone caulk between the tiles and the wall, covering all potential gaps.
- Seal all tiles and grout near the sink area with a penetrating grout and tile sealer. This adds water resistance. Reapply yearly.
- Choose smaller grout lines when tiling near sinks. The wider the grout lines, the more opportunity for moisture issues. Mosaic sheets or 1 inch subway tiles minimize grout lines.
- Ensure any tile near or beneath windows is properly sloped on the top surface, so condensation cannot pool.
Taking steps to properly seal and protect the tiles closest to sinks, windows and countertops maintains the beauty of your new backsplash and prevents costly water damage issues.
FAQs About Tiling Over Granite Backsplashes
Can you tile over granite backsplash with thinset mortar alone?
No, thinset alone does not provide a strong enough bond on a smooth granite surface. A primer or bonding agent should always be used first to prepare the granite for maximum adhesion.
What thinset mortar is best for tiling over granite?
Use a polymer or latex-modified thinset specifically engineered for tiling on smooth, non-porous surfaces like granite, marble, or ceramic tile. These provide a much stronger bond.
How long does the thinset need to cure before grouting?
Allow the thinset mortar to fully cure for at least 24 hours before applying grout. This prevents tiles from shifting or loosening up.
Should sanded or unsanded grout be used over granite?
Unsanded grout is recommended. It is smoother and fills narrow grout lines more effectively. Sanded grout is more prone to scratching the slick granite surface over time.
What size trowel notch should be used?
A 1/4 inch square-notched trowel is ideal for achieving the proper mortar thickness and coverage on the back of each tile.
Should backsplash tiles go all the way to the bottom of granite countertops?
It is recommended to leave a 1/8 inch gap between the bottom tiles and the countertop. This allows room for expansion and prevents cracking grout lines next to the granite.
Installing a tile backsplash over an existing granite backsplash can completely transform the look of your kitchen. With proper planning, surface preparation, quality installation and care taken around sinks and windows, you can achieve beautiful results that will last for decades. The project does require some additional labor, skill and the right materials. But with this helpful guide at your side, you can tile over granite backsplash successfully and economically.