There are two basic options for shower rod installation: permanent shower rods or spring tension rods. Permanent shower rods offer more stability and are safer if they're grabbed when someone slips in the shower. Spring tension rods can be installed without marring ceramic tiles, but over time they tend to slide out of place no matter how much tension is initially applied. If permanent installation is preferred, the right tools and a slow and steady hand can get the job done without cracking ceramic bathroom tiles
Use a tape measure to mark the locations of the holes. To be sure the shower rod is level, measure from the floor or bathtub up to the desired height on both walls.
Place pieces of tape on the walls according to your measurements. Mark the locations of the drill holes with a pencil. The tape helps to prevent the drill bit from slipping against the tile when you begin drilling.
Put on eye protection. Hold the drill firmly and begin drilling at a slow rate of speed. The drill should be held at a right angle to the wall so the bit will go directly into the tile. Drilling at an angle may cause the tile to crack.
Insert anchors into the drilled holes, followed by the remaining hardware. If the shower rod is adjustable, screw in both brackets. If it's not, screw down one of the brackets and insert one end of the rod into the bracket. Position the other bracket without screwing it down, then insert the other end of the rod and screw it down.
"Measure twice, cut once" is the rule for avoiding mistakes. Check your measurements at least twice before drilling the holes. Have more than one bit on hand and inspect the bit after you've drilled a few holes. If it's dull or discoloured, replace the bit. A dull bit is more likely to cause the tile to crack. Drill as close to the centre of the tiles as possible. Drilling at the ends of tiles may cause cracking.
Resist the temptation to speed up the drill to make the job go faster. Don't apply too much pressure when drilling; let the drill do the work.