Manufacturers offer a variety of shower-tub enclosures with sliding glass doors. Before you buy a do-it-yourself kit, measure your tub carefully. The kit should include instructions and all materials needed for the job:
two tempered glass doors, the top and bottom tracks in which they slide, the vertical side rails into which they fit to form a splash-proof seal, and hardware (you may want to use longer screws than those provided). Special caulking should also be provided for sealing the bottom track.
If necessary, use a hacksaw to cut the top and bottom tracks to fit. Center the bottom track on the tub’s ledge and mark where its ends meet the walls. Position the side rails on the marks, using a combination square to make sure each is vertical. Outline each rail on the wall, and mark the holes for fasteners. Then remove the rails and drill holes for the fasteners, using a masonry bit to cut through ceramic tile.
Apply the caulk to the tub ledge and press the bottom track into it, aligning the track with the marks on the walls. Interlock the side rails with the bottom track and fasten them to the was. Then attach the top track; in most models, it is simply pushed down onto the side rails. Insert the doors’ rollers in the appropriate track [depending on the model) and slip the opposite edge between the guides in the other track.