How to Make Cut Out Shelves in a Shower Wall

Locate the studs behind the shower wall with a stud finder. The shelf should fit between the studs to protect the structural integrity of the shower frame. Mark the locations of the studs on the shower wall.

Remove the tiles where the shelf will sit by tapping along the grout between the tiles with a chisel and hammer. Pry the tiles from the backer board with a pry bar.

Cut the outline of the recessed shelf area through the cement backer board with a reciprocating saw. The height of the recessed area should be tall enough to accommodate shampoo and conditioner bottles, and wide enough so that the studs serve as the sides of the shelf area.

Cut two sections of 2-by-4-inch pressure-treated lumber to the width of the shelf with a circular saw. Apply waterproof sealant to the lumber sections with a paintbrush.

Place one of the lumber sections between the studs so that the top edge is flush with the bottom of the shelf cutout. Insert 4-inch wood screws through the lumber section into the side studs at 45-degree angles, using a drill equipped with a screwdriver bit. Repeat this process with the remaining lumber section, placing the bottom edge of the lumber flush with the top of the cutout.

Apply waterproof sealant to the studs between the top and bottom lumber sections.

Measure the interior depth of the cutout with a measuring tape. Score a section of cement backer board to fit with a utility knife, using a metal straightedge as a guide. Snap the backer board along the score lines on the edge of a sturdy table.

Apply construction glue to the back of the cement backer board and place it inside the cutout to form the back. Apply thinset mortar to the backs of 4-inch ceramic tiles with a trowel and attach them to the backer board, starting with the bottom course. Tap the tiles into place with a rubber mallet. Cut the tiles as needed to fit with a wetsaw.

Measure the interior depth of the cutout. Cut 4-inch tiles to this depth with a wetsaw. Apply thinset mortar to the backs of these tiles and place them along the bottom, top and sides of the shelf cutout, tapping them into place with a rubber mallet. Cut tiles to width as needed to fit the corners.

Apply grout to the seams between the tiles with a grout float. Wipe away excess grout with a damp sponge.

Insert a caulk tube into a caulk gun and snip the tip of the tube at a 45-degree angle with scissors. Press the caulk gun trigger until caulk comes out of the tube tip. Apply caulk along the inside and outside corners of the cutout.