How to Frame a Shower in a Basement

Determine the location for the basement shower stall. To save time, the stall should be located over an existing floor drain.

Measure the planned exterior width, depth and height of the shower stall with a measuring tape.

Measure four pieces of 2-inch by 4-inch pressure-treated lumber 4 inches longer than the width of the shower stall. Measure another four pieces 4 inches longer than the depth of the stall. Cut the lumber sections to length with a circular saw.

Miter the ends of the eight pieces at 45-degree angles with a miter saw. Fit two length sections and two depth sections together to form a square or rectangular bottom plate for the shower stall frame. Fit the remaining length and width sections together to form the top plate of the frame.

Drill two pilot holes through each corner of the top and bottom frame plates. The pilot holes should be slightly smaller than the diameter of your wood screw shafts. Insert and tighten 4-inch wood screws through the pilot holes with a screwdriver to secure the corners of the frame plates.

Measure and cut sections of 2-inch by 4-inch lumber to span the interior width of the bottom frame plate. You need one section for each 12 inches of the frame's depth. Set the sections inside the bottom frame plate at 12-inch intervals on center. Drill pilot holes through the bottom frame into the ends of the interior sections and secure the sections with 4-inch wood screws.

Set the bottom frame plate in the desired location of the shower stall. Cut a piece of 3/4-inch thick plywood to the interior width and depth of the bottom frame plate. Note the position of the floor drain and mark it on one side of the plywood with a pencil.

Place the plywood section on the bottom frame plate. Drill pilot holes through the plywood into the frame plate sections and secure the plywood to the plate with 4-inch wood screws.

Measure and cut four sections of 2-inch by 4-inch lumber 4-inches shorter than the height of your shower frame. These sections form the corner studs of the frame. Stand one stud on a corner of the bottom plate, drill pilot holes at 45-degree angles and secure the stud with 4-inch wood screws. Repeat the process for another stud.

Place the enclosed shower unit on the bottom frame plate so that it meets the first two corner studs. Position and secure the remaining two corner studs. Place the top frame plate on top of the studs, drill pilot holes at 45-degree angles and secure the top plate to the studs with 4-inch wood screws.

Cut sections of 2-inch by 4-inch lumber to 4 inches shorter than the height of your shower frame to make interior studs. You need one interior stud for each 16 inches of depth on both sides, and for each 16 inches of width on the back.

Stand the interior studs inside the frame on the sides and back at 16-inch intervals. Drill pilot holes through the interior studs into the top and bottom frame plates and secure the studs with 4-inch wood screws.

Cut sections of 2-inch by 6-inch pressure-treated lumber to fit between each stud on the sides and back of the shower. These sections help provide additional support for the shower pan. Rest the supports on the bottom frame plate between each stud, drill pilot holes through the supports into the studs and secure the supports with 4-inch drywall screws.

Cut a drain hole in the plywood on the bottom frame plate with a keyhole saw, using the shower pan's drain hole as a guide.