Installing support bars on bathtub ceramic tile
If using a spade bit, buy two bits, a small one to drill a piolet hole then advance to the size that you need, if you have someone to help you can have them to spritz the bit with water constantly while you are drilling as the bit will get hot, you can also apply a piece of tape on the tile to help keep it from chipping out while drilling.....they also make a diamond bit for drilling tile and glass. Check at your local hardware store or Lowes, Home Depot, Menards, etc.....
Use a nail set and a hammer (gently) to break the glaze where you wish to drill. Then, using a tile bit or carbide tipped masonry bit, slowly drill your hole through the tile. If you use a hammer drill, turn the hammer action off. It will increase the chance of breaking the tile immensely. EDIT: Masonry bit works very well on ceramic, marginally well on porcelain.
Put a piece of masking tape over the area to be drilled. Drill hole where desired with a masonry drill bit. Don't worry this is a simple operation. Just go slow with the drilling and the tape should keep the tile from cracking.
Pretty much what these guys said, but i would recomend using a masonry bit with a hammerdrill. I not only rotates the bit like a drill but also has a back and forth motion like a hammer hitting a nail. Makes it easier to drill and extends the life of the bits.
