How to Frame a Shower Alcove

Remove the wallboard and floor coverings in the area where the shower will be installed. Thoroughly clean the area. Discard all materials removed.

Measure the shower base and mark its dimensions on the floor. Measure from the center of the drain pipe to ensure that the drain will be centered within the alcove. Nail blocking (short lengths of 2-by-4 lumber) between the studs in the existing walls to provide a surface to anchor the alcove walls.

Cut two matching lengths of 2-by-4 lumber for each wall to create the sill and cap plates. For each wall, lay out the location of the studs and plumbing on the new sill plate and the cap plate. Attach the sill plates to the subfloor and the blocking in the existing walls with deck screws and panel adhesive. Make sure they are square to the existing back wall and are the correct distance apart for the shower pan to fit.

Align a straight 2-by-4 next to the sill plate and mark the ceiling where the board touches. Extend the line directly above the sill plate. Attach the cap plate to the ceiling at the line. Check with a level to ensure that the cap plate is in line with the sill plate. Repeat this for the other sill plate.

Measure the distance between the cap and sill plates of each wall. Cut 2-by-4 boards to that length, ensuring that they fit snugly between both plates without deforming the joists above. These boards will be used as studs within the wall.

Install the 2-by-4 studs at the locations outlined on the sill and cap plates. Check that they are level and plumb with a spirit level. Attach them to the sill and cap plates with deck screws inserted at a 60-degree angle (toenailing).

If necessary, drill holes in the sill plate to run the plumbing for the shower. In the stud cavity of the wall where the shower faucet and shower head will be located, mark the faucet and shower head locations at 48 inches and 72 inches, respectively, from the floor. Attach 1-by-4 cross braces between studs centered on the reference points for the faucet and shower head. They should be positioned flush with the back edges of the stud to provide space for the faucet. These braces will anchor the faucet assembly, shower head and by extension the plumbing pipes within the wall.