How To Prep a Fireplace for New Tile

Renovating a fireplace can transform the look of a room, and it may be easier than you think. Whether you’re updating an outdated design or starting fresh, prepping your fireplace for new tile is the first step. This process involves removing old materials, assessing the surface, and creating a clean slate for your new tile installation. In the video above, Jenn Largesse from House One covers phase one of her fireplace wall makeover and upgrades her mantel with new molding. We’ll break down the process from start to finish below.

Tools and Materials for New Fireplace Tile Prep

Gather the following materials before you get started on this DIY project. 

• 1×2 trim
• Caulk
• Drywall
• Drywall screws
• Dust mask
• Plastic furniture covers
• Specialty screws
• Tile backer board
• White paint

Removing Existing Materials Before Installing New Tile

Before you can install new tiles, clear the way by removing old materials. This process requires careful demolition to avoid damaging the underlying structure.

Taking Off Molding and Trim

Start by removing the molding along the wall and at the base of the mantel. If you plan to reuse any of the molding, take extra care during the removal process. Follow these steps:

1. Score the seam with a utility knife to prevent splintering.
2. Use a thin putty knife to open the joint.
3. Carefully use a pry bar and hammer to remove the molding.
4. Begin at an outside corner for easier removal.
5. Work your way down the length of the molding.

Next, remove the transition molding between the tile and flooring using similar methods. This step creates a clean edge for your new tile installation.

Pro Tip: When reusing molding, never hammer finish nails back out through the face of the trim. Banging on a nail’s tip will cause the recessed nailhead to snag the wood fibers and splinter the molding’s surface as it exits. Instead, pull each nail through the back of the molding to preserve the finished face.

Technique Detail: When removing molding, use two pry bars for best results. Work one pry bar gently between the wall and one end of the molding, as near to a nail as possible. Wiggle open a gap, then insert your second pry bar on the other side of the nail. Rock the two bars back and forth to work the nail loose, then continue walking the bars down the strip, loosening each nail in turn. If you feel yourself pulling hard, slow down and look for any fasteners you may have missed.

Removing the Mantel

Removing the mantel requires patience and careful maneuvering. Work around the edges with a pry bar to find a loose spot, and concentrate on that area to gain leverage. Gradually work the mantel free. Remove any mounting blocks and set them aside for reinstallation.

Removing Old Tile

With the mantel out of the way, you can focus on removing the old tile. In some cases, tiles may come off easily with minimal effort. Use a pry bar to apply gentle pressure to each tile, remove them from the surround, and set them aside. Remove the hearth tiles with the same gentle pressure as well as any metal edge trim. Vacuum the area after all tiles are removed.

Technique Tip: For hearth tiles bonded with thinset mortar, a pry bar alone may not be enough. According to This Old House Magazine, you can rent a demolition hammer with a chisel bit to chip away old hearth tiles and the mortar underneath, leaving the concrete hearth base and firebox floor intact. Be sure to wear eye and ear protection and a dust mask when using a demolition hammer.

Assessing and Preparing Surfaces for New Tile Installation

Once the old materials are removed, it’s time to evaluate the condition of the underlying surfaces and prepare them for new tile.

Evaluating Wall and Hearth Conditions

Inspect the wall and hearth base. If there’s excessive mortar stuck to the drywall or if the hearth base is plywood, it may be best to start with fresh surfaces. Smooth surfaces will make the installation of smaller tiles much easier.

If the hearth substrate is plywood, cut a sheet of backer board to fit the area, score it with a utility knife, and snap it along the score line. Glue the backer board to the plywood with construction adhesive, then screw it down with fasteners placed every 12 inches. For a concrete-slab substrate, skim a coat of thinset mortar mixed with latex additive onto the surface using the unnotched edge of a trowel to fill voids and smooth it out. Allow it to dry to the touch before continuing.

Prepping the Surround: When evaluating an existing brick surround, scrape or chisel away any high spots — you can find these by pulling the edge of a trowel over the surface — as well as any crumbly or loose material. For a tile installation, trowel a thin, flat layer of mortar over the old brick and wait a day for it to harden. Then set the tile in thinset on this new surface. Avoid using mastic near a fireplace, as it can soften with heat.

Preparing the Wall

To prep the wall for new tile, take these steps:

1. Use a saw to cut out the old drywall, ensuring the seam falls behind the mantel and on a stud.
2. Remove the old drywall carefully. This is the messiest part of the job, but a wet/dry vacuum, bucket of water, and sponge can help minimize dust.
3. Install a new piece of drywall using drywall screws.
4. Confirm that the new drywall matches the thickness of the existing wall for a flush finish.

Preparing the Hearth

For the hearth, follow these steps:

1. Remove the old plywood base.
2. Choose an appropriate tile board (such as HardieBacker).
3. Cut the tile board to fit, including notches for the mantel legs, using a jigsaw fitted with a coarse wood blade.
4. Secure the tile board with specialty screws designed for cement board.

Updating the Fireplace Mantel

Now, it’s time to add your personal touch. Modernizing the mantel can transform the overall look of your fireplace. Here’s what Largesse did:

• Cut the legs shorter to lower the mantel height
• Trimmed the top edges to accommodate built-in cabinets
• Removed and updated decorative elements like flutes
• Replaced old trim with new 1x2s for a modern look
• Applied a fresh coat of paint

After updating your mantel, reinstall it by remounting the blocks on the wall, positioning the mantel, and securing it in place.

To create a clean, finished look, choose metal edge trim that complements your new tile. Apply adhesive to the back of the trim, and carefully position and attach the trim to the firebox edges.

Preparing for Tile Installation

With the prep work complete, you’re now ready for tile installation. Select appropriate tiles for a fireplace surround. Opt for materials that can withstand high temperatures and are suitable for fireplace applications.

Plan your tile layout for the best visual impact. You could always add a decorative tile pattern or use a uniform design for a sleek look. Then, gather the tools and materials you’ll need for tiling, including tile adhesive, a tile cutter, and grout.

By the end of this project, you’ll have a gorgeous, updated mantel that is ready for tiling. Head over to Part 2: How To Tile a Fireplace to find out how you can upgrade your living space with gorgeous tile.