Marble is a natural metamorphic rock that's used widely as a building and decorative material. Its elegant upscale appearance makes it the material of choice in many fancy restaurants, hotels, monuments, and even in the home setting. In its purest form, marble is sparkling white in appearance, coming from the intense pressure and heat from the metamorphism of limestone during its formation. Various mineral impurities such as clay, silt, sand, iron oxides, and chert present in the limestone as layers or grains give the marble, during metamorphism, its characteristic multicolored swirls and veins.
The porous stone, however, requires sealing. It should also be said that marble scratches and stains easily and is more susceptible to damage than ceramic tile and other natural stones. Marble flooring, therefore, does require some degree of maintenance, but it can be easily polished.
In its purest form, marble is sparkling white in appearance, coming from the intense pressure and heat from the metamorphism of limestone in the ground. Various mineral impurities such as clay, silt, sand, iron oxides, and chert present in the limestone as layers or grains give the marble, during metamorphism, its characteristic multicolored swirls and veins.
Can a Marble Floor be Repaired?
The problem with marble is that it is a bit fragile and can be easily damaged or cracked from the impact of an object dropped to the floor or possibly from the constant pressure from a heavy piece of furniture. So no matter how careful you are with your marble floor, accidents tend to and do happen and they can leave you with a damaged floor tile. But on the plus side, however, you don't have to live with a cracked tile or even replace the whole floor.
A marble floor tile cannot be fixed once it's cracked, but with the proper method and tools, it can be removed and replaced with a new tile without damaging any of the tiles next to it. But since marble is not manufactured but instead comes from a rock formation somewhere in the world, your biggest challenge when you need to repair your floor might be to find a perfect match for the broken tile with the same veining patterns and colors.
Unless you're lucky enough to have leftover tiles from the original installation, or possibly from the original supplier who can still get his marble from the same source, you might be caught having to look for a match close enough to make your repair inconspicuous. But coming from a natural product, however, it only needs to be as perfect as the colors of the swirls with the right purity of color from the limestone.
The degree of difficulty in removing a damaged tile can also depend greatly on the method initially used to install the flooring. The marble could have been installed using the older method of laying the tiles in a bed of mortar or the more modern method using thin-set adhesive, the difficulty in removing it lying with the types of bonding agents used in the mix. The method and tools used to remove the tile and the undercoating from the substrate, however, remain basically the same, from breaking the damaged tile and chiseling out the tile and mortar.
Step 1 - Finding a Match and Setting Up
Before you begin to break up and remove the tile, check around to find a suitable replacement tile that matches your floor. With a little luck, you'll find a few leftovers from the original installation, but if not, you should try to locate the original supplier, or if that's not possible, you'll need to shop around at different suppliers to find a new matching tile. While shopping for supplies, make sure to pick up a small amount of grout to match the grout already on your floor and thin-set.
For extra protection for the tiles surrounding the extraction site of the damaged tile, you could cover up the adjoining tiles with cardboard or heavy paper and tape it to the floor about 1/4 inch from the grout joint, leaving the damaged tile uncovered. This can keep the tools, shards, or other objects laying around from scratching the good tiles.
Step 2 - Removing the Grout
The grout inside the joints around the broken tile first needs to be removed, preferably with a grout saw or an oscillating tool with a grout blade. Carbide blades are the most popular, selling at a moderate price and able to handle the toughest grout but for the toughest jobs, you can get it done much faster with the more expensive tungsten steel blades.
But before starting, make sure that you are wearing safety glasses and a particle mask to protect you from any of the grout dust being generated. While using such tools you must remain careful not to chip the edge of the adjacent tiles as you grind out as much of the grout as you possibly can, making it easier to remove the tile.
Step 3 - Breaking Up the Tile
Once you have all the grout out from the joints, you can use one of two methods to get the tile ready for breaking it up. But first, make sure you're wearing safety glasses or goggles and gloves as sharp shards from the marble will be flying off the tile risking to harm you.
In the first method, you can use a center punch or even a nail set to further crack the tile up. Place the center punch or nail set in the center of the tile and strike it with sharp hammer blows until several cracks start radiating from it over the marble tile.
The other way of doing it is using a drill and a small ceramic drill bit to bore holes through the tile to weaken it and allow you to break it up easier. Several holes can be drilled over the tile surface before using a cold chisel and a hammer to break the tile up further into smaller pieces.
Step 4 - Removing the Cracked or Broken Tile
You can now insert the sharp corner of a cold chisel into a crack or a bored hole of the tile, striking the chisel with sharp blows of a hammer to break it up into several smaller pieces and off their thin-set. Remove every smaller piece and dispose of them in the garbage. You can remove the remaining pieces still stuck to the thin-set by tilting your chisel at a shallow angle so that the cutting edge does not damage the substrate beneath. Tap lightly with a hammer to get it to slide under the pieces of marble prying it off the thin-set.
Step 5 - Cleaning Down to the Substrate
Once you've removed all the tile pieces from the substrate, you should clean up the surface with a broom and/or a vacuum cleaner. This will give you a better view as to where you still have the remaining thin-set to remove. You can use your hammer and chisel to lightly strike the remaining thin-set and break its bond with the floor, taking care not to hit too hard and damage the subfloor. The loosened adhesive and mortar can then be scraped off with a metal scraper. Keep cleaning up as you go.
Once you're down to the substrate, you can finish smoothing off the underlay using coarse and medium grit sandpaper to even off any rises and depressions making the surface as flat as possible. The more noticeable dents and depressions should be filled with a leveling compound.
Step 6 - Getting the New Tile Ready
As previously mentioned, marble is a very porous material and to avoid any risks of staining the replacement tile during its installation, it's always a good idea to seal it beforehand. A marble sealing compound can be applied with a foam brush to create a barrier to prevent thin-set or any other material used nearby to stain it.
Following the manufacturer's directions, mix a small amount of thin-set—just enough to cover 1 tile—and apply it with a 1/4 inch notched trowel to the back side of the replacement tile. Take the tile and deposit it carefully down into place then press the tile down by hand firmly to embed the tile into the thin-set. To make sure to maintain an even spacing from the other tiles already in place, you should use plastic spacers at each corner to keep an even grout joint all around.
Finally, using a straight piece of 2x4 about 3 feet long, you'll have to level off the new tile to come even with the rest of the floor, or at least with the tiles surrounding it. Start by removing the tape and paper or cardboard used to cover the adjacent tiles. You can then lay the piece of lumber on its edge over the tile and tap it lightly with a rubber mallet to set the tile into the thin-set to where it will be at the same height as the surrounding flooring.
Repeat this procedure while aligning the 2x4 in different directions. You shouldn't tap it too hard though, to avoid risking breaking the tile, but just hard enough for the thin-set to accept it.
Step 8 - Cleaning Around the Tile
Get a sponge, a clean cloth, or a rag and a bucket half-full with warm water to wet and rinse your cloth. Use the wet cloth to wash any thin-set adhesive from the tile, and rinse it again and again until the tile is completely clean and free of any smears. A flat screwdriver can also be used to slide inside the joint between the tiles and remove the excess thin-set seeping out from the groove, as this joint has to be empty to allow for proper grouting.
After a couple of hours, the tile spacers placed at each corner of the tile can be removed. The thin-set should be left to set and dry for 24 hours before applying the grout.
Step 9 - Applying the Grout
There is always a risk that the grout might stain the surrounding marble, so to prevent such an occurrence, it's always a good idea to first apply a sealer coating to the tiles that surround the repair area before applying grout around the replacement tile. Make sure, though, that the sealer has completely dried before proceeding with the grout.
The grout should be mixed according to the manufacturer's directions. You can use a trowel to apply the grout onto the grout joint, filling the joint around the complete perimeter of the replacement tile. The grout is then pressed into the groove with a grout float, which held at a slight angle helps to pack down the grout into the joints.
The excess grout can then be wiped off with a damp sponge, rinsing often to remove most of the haze that might form on the surface of the tiles, including the surrounding ones. The final powdery residue can be removed with a dry cloth.
Step 10 - Sealing the Grout Joint
Grout being naturally porous stains easily so it needs to be sealed to prevent it. Most installers don't bother doing it because of the grout's curing time, but it is something that should be done to keep the grout looking its best.
Once the grout has completely dried, apply a grout sealer as recommended by the grout manufacturer. The sealer is applied using a foam sponge or a small paintbrush. After 10 minutes, you can test with water and then reapply as needed.
Step 11 - Sealing the Floor
It is recommended for a stone floor that it should be sealed every 6 to 12 months, so now might be a perfect time to seal the entire floor surface as this may very well help the replacement tile blend in with its surrounding floor area.
More related articles are also available for reading from the following links such as “How To Repair Marble Floor Etching”, “Marble Floor Restoration Mistakes to Avoid”, and “Installing Natural Stone Floor Tiles in Your Bathroom”.