Many homeowners prefer to use tension rods to hang their shower curtains -- these are spring-loaded and lock against opposite walls of the shower alcove. The great thing about tension rods is that you can remove them without leaving a trace. But if you have a heavy shower curtain, a tension rod might not support it. The alternative is a more permanent rod with screw-on flanges. These are easy to install on wood or drywall, but because you have to drill pilot holes for the screws, you may find installing one in a tile enclosure slightly challenging.
Installing a Tension Rod
Feed the rod through the rings on your shower curtain. Because this type of rod has a transition point between a large diameter section on one side and a smaller-diameter one that fits inside it, you should consider using large plastic hooks. They slip over the transition more easily than thin metal or plastic hooks.
Grasp the large-diameter section of the shower rod with one hand and the smaller-diameter section with the other, and turn the smaller one counterclockwise with respect to the larger one to lengthen the rod. Stop when the rod is about an inch shorter than the width of the shower or tub enclosure.
Hold the rod in the approximate place you want it and keep unscrewing until both ends are in contact with the walls. Keep twisting to increase the tension and lock the rod into place.
Put a level on the top of the rod, and adjust one end to make the rod horizontal, if need be. Then unscrew the sections a bit more to increase tension until it's difficult to move either end.
Open and close the shower curtain a few times to make sure the rod doesn't move.
Installing a Screw-On Shower Rod
Unpack the shower rod from the box and assemble it according to the instructions. You may have to insert the smaller of the two sections into the larger one, and you may also have to install a holder onto each end. Some units come pre-assembled with the holders already installed.
Lengthen the rod to the approximate width of the shower or tub enclosure opening, and hold it in position. The shower curtain should not be hanging on the rod at this point.
Pull the sections apart until both holders are in contact with the wall, and then place a level on the top of the rod and adjust one end until it's horizontal. Mark the positions of the screw holes in the rod holders on the wall, using a felt-tip marker, and then take the rod down.
Drill a pilot hole for a screw anchor on each mark, using a drill bit with the same diameter as the anchor you use. Plastic conical wall anchors are strong enough to support a shower rod -- make sure the ones you use are the same gauge as the screws you're using.
Tap a screw anchor into each hole; if the hole is the right size, you should need a hammer to fully seat the anchor flush with the wall.
Thread the rod through the shower curtain hooks. Put it back in position, and hold it there while you drive a screw through each hole and into a wall anchor, using a drill and No. 2 Phillips screw bit. You may need a helper to hold the shower rod while you drive the screws.