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Use a tape measure and measure the width and length of the space you want to cover with subway tiles. Multiply these numbers by each other. This will give you the total area you want to tile. Afterwards, add 10% to the total to cover potential waste. If you have a 10-foot (3 m) section that is 2.5 (.76 m) high, you have an area of 25 square feet (7.6 square meters) to cover. To cover waste, you’ll add 2.5 square feet (.76 square meters) in addition. This will give you a total of 27.5 square feet (8.4 square meters) of subway tile you will need to purchase. Use a flathead screwdriver and unscrew the plastic covers from the outlets and light switches. After removing them, place the screws and the covers in plastic bags so you don’t lose any pieces. You’ll replace the covers once you’ve installed your backsplash. Start by determining how many tiles can fit vertically and horizontally in the area you want to cover. Next, figure out where you need to place partial pieces of tile (pieces that you will cut). A lot of this depends on your taste. Finally, take a pencil and draw on the wall where you plan to place individual tiles.  Factor in 1/8th of an inch (.32 cm) between tiles and the wall for grout lines. You may want to choose between centering whole pieces of tile or starting at the top with whole pieces and finishing the bottom with cut/partial pieces (if there isn’t enough space for whole pieces). After you’ve sketched your design on the wall, you should assemble all of the pieces you need to complete your project. It is best to lay out your pieces on a large table or on the floor in another room. This way, you’ll be able to match the pieces to the places on the wall where they will go. Don’t cut any partial pieces yet. Set aside all of the pieces you’ll need to cut partial pieces. After placing full pieces on your wall, you may find that the size of the partial pieces you’ll need is a little different than what you anticipated. Use a cloth or plastic to cover anything you want to protect from adhesive, grout, and caulk. Most importantly, place cloth or plastic over your countertops, on appliances, and on any furniture in the immediate area. Secure drop clothes to countertops and appliances with painter’s tape. Take the time to systematically cover the edges of cabinets, appliances, and woodwork. This way, you’ll protect cabinets and more from being stained with grout or caulk. When your sandpaper wears out and isn’t as abrasive, use a fresh piece. Make sure you sand the entire surface that you are tiling. Sanding will make it easier for the tile to adhere to the wall.

Summary:
Measure the area and purchase 10% more tile than you need. Remove outlet and light switch covers. Sketch your tile design on the wall. Lay your tile out. Place a cloth or plastic cover over your countertops and appliances. Cover the edges of cabinets and appliances with painter’s tape. Rub 80-grit sandpaper back and forth on the area you are tiling.