Whether the cut is straight or curved, and the tile is ceramic, glass, or stone, there’s a tool and technique to use for the perfect fit.
Snap cutters and nippers
Most ceramic wall tiles are thin and easy to cut. A snap cutter, which uses a scoring wheel guided by two rails, works well for straight cuts. The trick is to score the cut with only one pass before pressing the lever to snap the tile. Tile nippers are a low-tech tool for curved cuts: First, score the cut with a carbide-wheel glass cutter, then use nippers to gradually pinch away the waste tile. Nippers leave a ragged edge, so use them where the edge will be covered by trim.
Wet saws with diamonds
For hard tiles, such as porcelain, and ceramic, which is softer, nothing beats a wet saw: It’s easy to use, gives predictable results, and is affordable to rent (about $75 per day). Fit the saw with a diamond-encrusted tile-cutting blade, keep the tray filled with water, and always wear eye and hearing protection. Mark cutlines with a wax crayon—pencil often washes away as you cut.
Glass: Cut carefully
For cutting glass tiles, the best tool is a wet saw with a special blade, electroplated with fine diamond fragments. (A regular tile blade—which has coarser diamonds— will chip glass tiles.) Take it slowly and you’ll get cuts as smooth as, well, glass.
You can also use a wet saw to cut complex curves: Mark the curve, then make multiple release cuts from the tile edge to the cutline. Your tile will look like a comb, with many thin teeth that easily snap off. To clean up the curve, carefully tilt the tile’s leading edge above the saw table and use the blade to gently grind away unwanted remnants.
Shaping cut-outs and drilling holes
Another curve-cutting approach, ideal for thicker stone and ceramic tiles or cutting a large hole for a toilet, calls for an angle grinder with a continuous-rim diamond blade, held vertically to follow a cutline. Cutting dry creates hazardous dust (wear a mask), and heat and vibration that can crack tiles—go slowly, with multiple passes.
To make straight plunge cuts for, say, an electrical box cut-out, use an angle grinder and a diamond blade, or a water-lubricated, hand-held tile saw. Another technique: Bore overlapping holes along the cut-out edge with a diamond coring bit, then nibble off the leftover bits with tile nippers.
You can drill a hole in the middle of a tile with a carbide masonry bit, and carbide-encrusted hole saws are available, but for ease and speed, the best option is a coring bit rimmed with diamond fragments. Unlike a hole saw for wood, it won’t have a centre spur to hold it in place. Until the bit has scored the tile surface, it tends to skate around. Scrap plywood with a V-shaped cut-out works as a jig to steady the bit, as does an adjustable wrench opened to the size of the bit. Cool the saw and tile with a spray bottle or squirt gun, or form a ring of Plasticine or window putty on the tile, and fill it with water.
How to lose your edge
When you cut tile—especially glass—the edges can be sharp or jagged. Smooth them with a few quick passes of an inexpensive diamond sharpening stone dipped in water.