How to Redo a Tub to Enclose a Ceramic Shower Stall

Go into the basement or crawlspace to examine old pipes and drains under the bath area, or cut open the wall to examine the condition of pipes and drains just above the tub faucet. Replace any worn plumbing and add new plumbing before the tilework begins. (Don't install new faucets or showerheads until the tilework goes up.)

Check the walls surrounding the tub to ensure that the wall framing is relatively plumb and level in all directions. Place a 4-foot carpenter's level horizontally at the top, middle and bottom of each wall. Look for the bubble to hit the center point of the level to define how much correction the wall framing will need. Check the walls with the carpenter's level vertically at several points, including the corners.

Take off drywall with a pry bar. Cut strips of wood shims, if needed, from plywood sections or solid boards, using a jigsaw. Nail shims to the studs facing the tub area to make the framework plumb and level. Check with the carpenter's level again to ensure the thickness of the shims is correct. Shave the shims down with a hand planer if adjustments are needed.

Apply backerboard--which will provide a good underlayment for tile--with backerboard screws. Cut the backerboard in sections to fit the space with a drywall knife, using a straightedge to make the cuts. Lay down a carpenter's level as a good straightedge to score and cut the backerboard. Staple rolled construction felt over the backerboard. Overlap the felt at least 2 inches at every seam to protect walls against water damage.

Draw a tile design on graph paper that will fit the shower walls. Snap a grid of chalk lines with a chalk box to define the exact placement of tiles on the walls. Trowel on laxtex mortar to hold the rows of tile. Be sure to caulk around the tub and plumbing fittings after all the tile is in place.

Cut aluminum shower-door tracking with a reciprocating saw to fit the tub's bottom edge, walls and along the top of the doors. Caulk the tracking and attach it to the walls and the tub edge according to the manufacturer's instructions. Lift the sliding shower doors onto the tracking with the help of friends.