Preparing to Install Ceramic Shower Tiling
Before you begin to install ceramic tile in your shower area, it is important that you take the necessary preparations for the project.
Step 1 - Order the Supplies
When you order your tile, make sure you have accurate measurements of the space. A plan drawn on graph paper can be very helpful. Be sure to order approximately 10 percent more tile than you need to allow for cuts and damage. Plus, the color of glazing often varies from shipment to shipment, so if you have to go back later to get more tile, you may find that the tile does not match exactly.
You'll also need to select the grout. Grout comes in different colors. If you decide to use a colored grout, be sure that it won't stain the particular tile you've selected. A practical consideration for kitchens might be that a dark grout does not show dirt as easily as a white grout.
Step 2 - Prepare the Surface
Before you start, clear away anything that will get in the way or get wet, such as rugs, towels, glass bathroom shelves, and other accessories. It's important to cover the drain with some tape so that debris won't fall down the drain and cause it to clog. Line the tub or shower with cardboard so as not to scratch them. Remove the baseboards and door and window trims by using a pry bar. Remove the faucet handles, escutcheons, shower heads, and spigots. If the walls to be tiled are wallpapered, it needs to be scraped off as the weight of the tile would pull it right off the walls.
Step 3 - Install the Backerboard
When you are tiling in a bath or kitchen where there is high exposure to water, "greenboard" or moisture-resistant drywall, should be applied over the studs as a basic wall surface. Then a mortar-based backerboard should be installed over the "greenboard" for the best tiling surface.
Backerboard was developed several years ago as a clean and simple method and compares in quality to the traditional but difficult route of doing a mortar bed. Backerboard is made of a ceramic aggregate core that is coated with a thin fiberglass mesh. It comes in 7/16-inch thick sheets and is applied similarly to hanging plasterboard. The height of the backerboard will pretty much determine the height of the tile job. Once the tile has been laid, a line of quarter-round tiles will cover up the rough edge of the backerboard.
If the tile is not going to go all the way to the ceiling, as it often will not, make some level layout lines at the correct height so you have a line to run the backerboard to. When laying out these lines, make sure that there will be at least one row of tiles above the shower head. Use a level to establish an accurate level line all the way around the surface to be tiled. Determine the height of the backerboard by measuring carefully so that when the tiles are installed up the wall, the spacing will be exact enough to eliminate any need to cut the tile along the top row.
Check the level of the tub. If you are working around a tub or shower pan that is not level and cannot be adjusted, cut your backerboard so that the cut edge is along the lip of the tub or shower pan and is at the same angle as the tub. If your tub can be adjusted to be level, do it before you put up the backerboard. If you are tiling around a shower, be sure that shower pan is correctly seated into position so that it is level and will drain correctly.
Creating a traditional mortar bed receptor for a shower base is better left to a professional. If you are doing a shower we recommend that you use a ready-made shower pan and seat it by following the manufacturer's recommended instructions.
Start with the backerboard that goes on the back wall since it requires the fewest cuts. Find and mark the location of the studs at the top and bottom of the wall. Later, when putting the backerboard up, you can snap a chalk line from point to point and know exactly where to nail. The backerboard should be nailed to studs that are a minimum of 16 inches on center. If you are going to be using a floor and wall tile adhesive, install the backerboard with the smooth side out. If using an epoxy or acrylic mortar, install with the textured side out. Also, if you're using epoxy or acrylic, be sure the room is well-ventilated as the fumes can be toxic.
Cutting the backerboard is easy. Make careful measurements. Then with a straight edge, score along your chalk line. The backerboard will then crack along that scored line when it is bent, just like drywall. Then turn the piece over and score the back to cut through the mesh on the other side.
Use 1.5-inch galvanized roofing nails so that the nails penetrate into the studs adequately, nailing at 6-inch intervals around the edges and in the center over the studs. Longer nails will be needed if you must penetrate both the backerboard and plasterboard. Nail heads should be flush with the surface, but not countersunk as it can cause the backerboard to crack or break. Joints should be close together but not tight. Some backerboard manufacturers require a nail and a large washer used at the edge for better holding. Check the manufacturer's instructions.
Position a ¼ inch spacer along the rim of the tub to hold the backerboard up slightly. Once all the backerboard is up, but before you lay the tile, fill the gap with silicone caulk to form a watertight seal. When making the holes for the faucets and shower head, measure very accurately.
Cutouts and holes for plumbing pipes and fixtures can be made by breaking through the fiberglass mesh with the edge of the head of a conventional hammer. For neater cuts, they can be cut by using a saber saw with a carbide blade or a masonry hole saw attachment for a drill.