Laying tile: A step by step guide
Ceramic tile is typically used in locations that get wet so before laying tile install an underlayment that is impervious to moisture. For this project, we used cement backer board. These thin, lightweight sheets of fully cured concrete provide a flat, solid, waterproof surface for the tile to adhere to.
Cut backer board to size with a circular saw, jigsaw or angle grinder with a carbide- or diamond-tipped blade. On a jobsite without electricity, use a utility knife and straightedge to score the backer board, break the board along the line, and then finish the cut on the other side with your knife.
Most brands of cement backer board have a front and back side, with factory printing on the board’s front side. Install this side facing out. Fasten the backer board directly over wall studs with nails or screws. When laying tile, most installers use a few nails to hold the backer board in place initially and then specially designed screws to secure it in place.
A collated screw gun with long strips of screws that feed automatically will allow you to fully fasten a sheet of backer board in a fraction of the time. Cover seams between pieces of backer board with adhesive fiberglass mesh tape and apply thin set mortar over the tape to help it fully adhere to the backer board and hide the seam.
When laying tile, the most important tile is the first one. If the first tile is set just a fraction of an inch crooked or out of square with the room, it will become more noticeable with each tile put in place after it and will be obvious when the job is done.
Measure the area and mark straight lines directly on the backer board to use as a guide. Determine how many full tiles will be needed to fill each row (horizontally and vertically) and then adjust so that you will end up with cut tiles of even widths along the edges. In some applications where you’ll be laying tile, you may want to adjust the starting point because of the difficulty in placing very small or oddly shaped tiles or simply because of how the finished project will look.
For example, in this project, four full tiles will fit across the space. Placing the first tiles on either side of the center line would require very narrow tiles to be added at either end. Centering one tile on the line decreases the number of full tiles to three, but it increases the size of the cut tiles on either end and ultimately creates a more attractive look.
Prepare a batch of thin set mortar. Many installers use 5-gallon buckets and a drill-powered paddle as a mixer. Follow the manufacturer’s instructions for the correct water-to-mortar ratio, adding water if necessary to obtain the proper texture.
Comb thin set over the backer board using a notched trowel. The square notches create ridges in the mortar that improve tile adhesion. Cover only as much area as you will be able to tile in 30 minutes and take care not to cover up your guide lines.
Working in one small area at a time will prevent the mortar from drying before you begin laying tile. In tight spaces where your trowel won’t reach to spread the mortar, you can “back butter” each tile individually. Use your notched trowel to spread mortar onto the back of the tile, creating the same raised ridges of thin set. Some installers also back butter when setting tiles that are 12 inches square or larger to ensure consistent coverage.
Position the first tile over the thin set and press it evenly into the mortar. Give the tile a slight twist as you work it into place so the mortar spreads evenly. Pry up this first tile and check the mortar coverage on the back. If there are bare spots on the tile, apply and comb more mortar and reset the tile. If 80 percent or more of the tile is covered with mortar, reset the tile and continue, using the same mortar thickness for the rest of the project.
Place tile spacers between tiles to create consistently sized joints. Check your progress regularly with a level and make adjustments as needed while the mortar is still wet. Once you near the edges of the thin set spread a new section of mortar and continue.
Measure the tile and mark the cut line, then align it with the cutter’s scoring wheel. Applying light pressure on the lever, make a single pass across the surface of the tile. When you reach the end, push down on the handle to break the tile along the line. To cut tile with a wet saw, position your cut line with the blade. With the blade spinning and the water spray directed at the point of contact, gently feed the tile through the saw until the cut is complete.
Once the tile is in place, most manufacturers recommend allowing at least 24 hours for the mortar to properly harden and create a tight bond with the tile. High temperatures or humidity can increase the time required for the mortar to fully cure.
Before mixing grout for laying tile, clean the area you’ve tiled and remove tile spacers. Grout is often mixed by hand so the installer can closely gauge and control the mixture. Add water sparingly, a few drops at a time, until the grout is similar in consistency to cake batter. Avoid mixing more grout than you can apply in 30 minutes to keep it from hardening in the bucket.
Apply grout to the tile surface using a hand-held rubber float specifically designed for the job. The float’s smooth face spreads the grout over the tile and forces it into the joints. Hold the float at a 45-degree angle and work diagonally to keep the float from catching on the edges of the tiles. Remove excess grout.
After about 20 minutes, the grouted tiles will appear hazy. Clean the tiles with a clean, wet sponge to remove the film. Use a damp sponge to smooth the grout lines and ensure an attractive end result.
–By Todd Brock