01 of 10
Gather Your Materials
Although natural slate is a durable flooring material, it is possible for individual tiles to become chipped, cracked, or scratched. In the case of chipping and cracking the problem is often caused by the adhesive layer beneath the tile becoming uneven. Scratches are usually caused by external forces acting on the surface of the material. In many cases it is impossible to repair damage to individual tiles requiring the entire piece to be replaced.
This project will walk you through the steps... required to remove the broken tile, repair the surface beneath it, and then replace it with a new piece. The photographs shown are of a solid gray slate with a natural clefted surface installed on a concrete underlayment. These instructions should be valid for all basic slate tile flooring installations.
Difficulty Level: Moderate
Time to Complete
1-2 Hour Labor 24 Hours Drying Time for adhesive and grout.
Carbide Tipped Grout Saw
¼” Notched Trowel
Piece of 2x4 Hardwood
Needle nose Pliers
Natural Stone Sealer
Matched Slate Tile
Note on matched materials: Slate is a natural stone so the exact color of any given type of tile is variable, which can make it difficult to find a piece that fits the rest of the floor. Finding a matching grout can also be a problem. If possible you should hold on to a few extra tiles, as well as some grout after the installation of a new slate floor.Continue to 2 of 10 below.
02 of 10
Remove the Grout Around the Broken Tile
Take your carbide tipped grout saw and run its blade along the grout line surrounding the broken piece. Be careful not to chip or scratch the any surrounding tiles as you work. Use a gentle but firm motion to remove all of the grout until the side of the tile is completely exposed.
More About Natural Stone Flooring
ASTM Standards For Stone Flooring
Sandstone Flooring Pros and Cons
Marble Floor Tile InformationContinue to 3 of 10 below.
03 of 10
Break the Surface of The Tile
Use a hammer to drive a nailset into the surface of the tile to puncture it in one or two places. This breaks the slate up so that you can remove it. Be sure to wear protective eyewear while doing this in order to guard your eyes against damage from flying chips or rubble.Continue to 4 of 10 below.
04 of 10
Remove the Tile Shards
Place the point of your chisel into one of the cracks and lightly tap the handle with a hammer to pry up the pieces of the tile. Start at the center of the piece, and work outward, being gentle and careful not to damage the surface of any of the adjacent pieces. As you work you should be aware that the cementboard underlayment beneath the tile can look a lot like mortar, so be careful not to damage it with overenthusiastic chiseling.Continue to 5 of 10 below.
05 of 10
Remove the Old Adhesive
If the tile was installed with thinset mortar use a putty knife to scrape the old adhesive away. If it was installed with poured mortar then use a chisel. Scrape as much of the adhesive away as possible, then use mid grade sand paper to smooth the area. When you are finished, fill any gaps in the underlayment with a floor leveling compound if it is a wood base or an epoxy-based thinset mortar if it is cementboard. You want the surface to be as flat and even as possible so that a firm connection... can be made with no gaps creating weak points under parts of the tile.Continue to 6 of 10 below.
06 of 10
Apply the New Adhesive
Apply the thinset mortar directly to the back of the tile using your ¼” notched trowel. Make sure that the entire bottom surface of the piece is covered. Then trace the edged side of the trowel through the mortar to create “rows” which will grip the surface of the underlayment.
Place the tile into position, pressing down until its surface is even with the surrounding pieces. You can twist it slightly to get it to sit more firmly in the mortar. As you position the piece, place tile spacers at each... of the four corners to ensure that your grout lines will be straight and even later on.Continue to 7 of 10 below.
07 of 10
Tap the Tile Down
Lay a piece of straight 2x4 wood across the newly placed piece so that the wood touches at least two adjacent tiles. Then tap it lightly with a wooden mallet to press the new tile down so that it rests even with its neighbors. You can use a level to ensure that you have the tile flush.
In the case of clefted slate the surface of the tile may be irregular, making it impossible to get it perfectly even with the rest of the floor. Focus on getting the edges of tiles such as these even with adjacent... pieces along the grout line.Continue to 8 of 10 below.
08 of 10
Clean the Installation
Once the tile is perfectly positioned use a small screwdriver to remove excess adhesive from around the seams. Take a wet cloth and wipe mortar off of the surface of the piece, and any adjacent tiles that may have been splattered during the installation. Then use a pair of needle nose pliers to carefully remove the spacers at the corners. Allow the tile to set for at least 24 hours before moving on. During this time do not walk on it or move it in any way.Continue to 9 of 10 below.
09 of 10
Grout the Tile
Once the adhesive is dry use your putty knife to apply grout to the seams. Try to be as precise as possible, using your fingers to direct the grout down into the gaps. Wipe off any excess that gets on the surface of the tiles with a cloth.
The grout should be left to dry overnight. When it is no longer malleable or moist to the touch, you can trail a wet sponge lightly over the surface of the seams to clean them up and remove any grout that is still stuck to tile surfaces along the line.Continue to 10 of 10 below.
10 of 10
Clean and Seal the Material
When you’re done clean the entire surface of the floor with warm water, making sure that you remove all dirt and debris. Allow this to dry thoroughly. Then use a rag or hand brush to apply a commercial grade below surface natural stone sealer to the entire floor. As you work, spread the sealer across the tiles in a thin even coat, and be sure to go back and smooth out any bubbles that appear.
The sealer will soak into the stone, creating an invisible barrier across it while also making the... individual tiles shimmer with enhanced color. This will help to blend the new piece into the rest of the installation.