Randy asks: What is the best way to drill ceramic tile for installing grab bars, shower rods, and other hardware? I didn’t have much luck with a carbide bit and even tried a hammer drill.
Steve Bliss, of BuildingAdvisor.com, responds: A carbide bit will work fine on soft wall tile, but floor tile and most wall tile used today are harder and require a diamond bit for easy drilling. Porcelain tile definitely require a diamond bit. Avoid hammer drills altogether as you risk cracking the tiles.
The best choice is a diamond core bit, which is hollow and comes in sizes from 1/8” to whatever size you need. Drill the hole larger than the screw diameter so the screw does not press against the tile.
To start the hole, hold the drill firmly at about a 45 degrees, starting the drill slowly and holding it firmly to keep it in place. Drilling through tape can help you keep the drill in place. Once the bit has cut a little groove, gradually shift the drill to horizontal and run the drill at full speed, spraying both the drill and hole frequently with water.
With the drill straightened out, you’ll fly through the material pretty fast. If you plan to reuse the bit, it’s best to clean it out after each hole. Some core bits have holes or slots to help with this process. Banging a nail or nail set through the hollow core can also help remove tile debris that builds up.
I’ve had good luck with bargain bits purchased on the internet, but don’t expect them to last for too many jobs.