Measure the width and height of the wall to find out how many marble tiles you need. Use measuring tape to take precise measurements of the area of wall you’ll be tiling. To find the area of your wall, multiple the length times the width, and then divide this number by the area of 1 box of the tiles you are using in order to determine how many to purchase. When you’re purchasing the floor tile, buy an extra package of tiles in case some get damaged while you’re hanging them.

For instance, if the wall is 10 by 12 feet (3.0 by 3.7 m), it is 120 square feet (11 m2). Then, if each box of tiles has 10 square feet (0.93 m2) of tiles, divide 120 by 10 to find that you need 12 boxes to cover the wall exactly. Then, you should add an additional box to account for potentially damaged wall tiles. Since the grout doesn’t take up much space between the tiles, and your small tiles likely won’t fit in the space perfectly, you don’t need to account for it in your calculations.

Use a chisel and hammer if you need to remove existing polished tiles. Put on a pair of safety goggles before you start removing the tiles. Then, place the chisel at a 45 degree angle between the tiles and hit the end of the chisel with the hammer to separate the tiles from the wall. Use the chisel to scrape between the tiles and the wall until they’ve all been removed.

It’s easiest to start removing cement tiles from a corner or from the top of the wall so you can place the chisel directly on the grout, which tends to be weaker than the tiles. Be careful while you’re removing the ceramic tiles. It’s easy to accidentally make a crack or hole in the drywall if you’re not holding the chisel at a 45 degree angle while you work.

Fill any cracks or holes in the wall with spackle. Once you’ve exposed the drywall underneath any existing common marble tiles, you’ll be able to see any problem areas. Use a scraper to apply the spackle and let it dry according to the package directions, which is normally about 4-6 hours.

For cracks and holes larger than 4–5 inches (10–13 cm), you may need to patch them with drywall. If you’ve never hung drywall, ask a professional for a quote to see how much it will cost to fix that area. If the wall doesn’t have tiles, it is probably painted or wallpapered. You can use the same method for repairing the drywall without removing the paint or wallpaper.

Sand the walls with coarse sandpaper to smooth any bumps. If you had to remove pre-existing tiles design or fix holes and cracks, there are likely bumps in the wall. You can tiles over it, but it needs to be smooth to prevent your new tiles from laying crooked. Look for 100-grit or 80-grit sandpaper, and wear a mask to protect your lungs from the particles in the air. If you’re sanding a large area, it might be easier to use an electric sander.

Wipe down the walls with a damp sponge to clear the drywall dust. Drip a sponge into a bucket of clean water. Then, starting at the top of the wall, drag the sponge all the way down the wall to clear off the dust. Rinse the sponge in the bucket and continue wiping until you’ve rinsed the entire wall. Wait at least an hour for the wall to dry completely.