15 Tips for Tile Installation
When it’s time to hit the hard stuff—tile—keep these tips in mind for a successful installation.
By Matt Weber
Tile has been around for thousands of years, and modern materials provide hundreds of design options. Not only does tile afford the installer a lot of creativity in the finished look of the project, but as a flooring material it does not burn, fade or easily stain when properly installed. It resists wear and can feasibly last as long as the substrate that supports it. The following are a few tips to keep in mind for your next installation.
1. A visual reference can make it easier to design a room’s tile layout. Sketch a scale drawing of the living space on graph paper, including measurements, walls and any other obstacles. Tile is sold in square-foot quantities, and graphing the area can help determine the quantity needed. Also, it’s wise to order about 7-percent extra to account for waste pieces and to have a little left over in case repairs are required.
2. Not only do tile subfloors need to be perfectly flat, but also strong and rigid. Any give or flexibility in the subfloor can lead to cracks in the grouts joints. Jump on the flooring in several areas of the room. If there are any signs of movement, then the floor should be reinforced prior to laying tile.
3. For floor tile, check the room for square. Use the 3-4-5 rule to check that the corners form right angles. Measure and mark a point 4 feet from the center along one wall. Measure and mark a point 3 feet from the center on the intersecting wall. A diagonal line between the two points should measure 5 feet if the chalk lines are at 90 degrees. In large rooms you can double the ratio (i.e., 6-8-10). If the room is less than 1/8-in. out of square within 10 feet, it can usually be disguised within the layout. However, if one wall is significantly out of square, then lay out the floor so the tapered tiles will run along the least noticeable wall.
4. For floor tile, check for level and flatness. Checking for level is particularly important if you’ll be adding wall tile. Set a 4-ft. level on the edge of a long, straight 2×4 to read over a large area. Swivel the boards to find and dips or bumps. Minor depressions can be built up with building paper, but a liquid floor leveler may be required for bigger dips. Plywood subfloors with high spots can be belt-sanded.
5. For wall tile, make sure the walls are plumb. With out-of-plumb walls, the tiles will necessarily have to taper in width as they progress up the corners, which can be very noticeable and unsightly on a wall. It may even be necessary to remove the wallboard and shim the framing or install new studs to ensure plumb walls.
6. Tile should generally be installed on a rigid underlayment, which resists movement such as swelling and contraction that can damage the finished flooring. A traditional choice is cement backerboard. However, fiber-cement board can be difficult to cut and generates a lot of dust from a saw blade. For tile installed over a sturdy subfloor, consider using a new polyethylene membrane that “uncouples” the thin-set mortar from the subfloor to protect against material movement. For vertical installations, some of the newer tile-board products made from polystyrene foam weigh considerably less than fiber-cement and are much easier to cut.
7. For bathtubs and showers, run a bead of silicone sealant along the edge of the tub where it meets the tile backerboard. For the best waterproofing, it’s smart to seal all backerboard joints in a shower enclosure before installing any tile. Once the tile is in place, avoid grouting the wall corners and beneath the first row. These areas need to be sealed a mildew-proof caulk.
8. A standard procedure for floor tile layout is the quarter method, in which the room is actually divided into four quarters to help sequence the layout. First step is to measure and mark the midpoint of all four walls. Snap intersecting chalk lines at the center point of the site, forming a square cross. Check that the lines form right angles. Start by laying a row of tiles in a dry run along each of the four lines, all the way to the walls, creating a cross of tiles in the center of the room. If necessary, use plastic spacers to keep the grout joints even. Lay tile starting from the center and working your way outward. Any cut tiles will be at the edge of the wall. All cuts should be the same size from one end of the room to the other.
9. For diagonal tile layout, use the center point established with the quarter method and snap lines across the two diagonals of the room creating an “X” on top of the cross. Then install the tiles as with using the quarter method. Make sure the lines are at true right angles and that the partial border tiles are equal in width.
10. Most professionals remove all baseboard trim before laying the tile. However if floor space is not a primary concern and the baseboard has a tall enough profile, you may be able to save time and labor by running the tile against the baseboards and concealing the joint with shoe molding.
11. The size of your grout joint is a personal choice, but keep in mind that larger grout joints are more likely to crack and attract more dirt. For the cleanest appearance with less maintenance, consider a joint as thin as 1/8 to 3/16 inch. If your design includes tiles of multiple sizes, consider using a 1/4-in. grout joint throughout, which adds consistency to the overall appearance.