Home Repair and Paint Guide

Drilling ceramic tile requires a carbide or diamond drill bit. Both are perfect for the task. You can find these at most home improvement and tool stores and the price is reasonable. 

Ceramic tile is very hard and breaks easily if not supported. If you drill too fast, the heat buildup will crack the tile. In order to prevent cracks and discoloration, use a variable speed drill and new drill bits. Don’t apply much pressure, just let the drill do the work. Use a very slow speed in the 100 - 200 RPM range. Don’t use any type of hammer drill on tile because that will shatter it like glass.

Since there is no way to score ceramic tile, you cannot use a punch to create a starting point for the drill. This causes the drill bit to wander over the surface, scratching it in the process. Use a piece of duct tape to keep the drill bit still until it bites into the surface. Again, don’t use much pressure.

To prevent overheating, keep the drill bit cool by dipping it in a small container of fresh cutting oil every 15 seconds. Wipe excess oil from the bit with an old rag to keep the tile and grout from being contaminated. You can buy this oil at a home improvement store or plumbing supply house.

Use diamond tipped bits for porcelain tile. These will do a satisfactory job as long as they are kept cool the same way as carbide bits. Once the drill bit cuts a cone-shaped hole into the tile, it will make good progress.

Large holes can be created using a hole saw that has diamond cutting teeth. The hole saw must be equipped with a pilot bit that drills a smaller hole at the center of where the larger hole is to go. The pilot bit keeps the hole saw from wandering. Don’t cut too fast. Hole saws must be operated at very low speed and with little pressure. Keep the cutting teeth cool by dipping into oil as for regular drill bits. Be sure to wipe away excess oil before continuing with the drilling process.

When drilling into an existing wall, be very careful of pipes or electrical wires that may be behind the surface. You could receive a very nasty shock if a wire is cut. A water pipe could also be nicked and start dripping behind the wall. This could go unnoticed for a long time and would completely wreck the wall backing as well as the floor. You can purchase a drill depth collar and set it so the bit cannot penetrate past the collar set point. Don’t let the collar slam into the surface because that would scratch or break the tile.