A Quick Shelf Recess for a Tile Shower

Maine tile contractor Tom Boucher shows how to quickly install a watertight recessed shelf opening for a tile shower using a pre-made box from Schluter Systems.

Checking Dimensions

The frame of the pre-built box measures exactly two inches. Boucher will account for this as he positions the box to match his wall tile layout.

Laying Out for Full Tile

Boucher marks the shower wall for his cut. He'll install the recess box so that a full tile will fall flush with the lower edge of the box.

Laser Accuracy

Boucher lays a laser guideline onto the wall to mark the spot for his box cut-out on the existing Kerdi-Board.

Finding the Stud

Bouchet probes with a razor knife to locate the edge of the wall stud behind the Kerdi-Board.

Tracing the Outline

Guided by the laser layout lines, Boucher holds the pre-built recess box face to the shower wall and marks its outline for the cuts.

Cutting Out

Boucher cuts out the Kerdi-Board to create an opening for the recess box.

Peeling Back

Boucher removes the previously-installed Kerdi membrane over a fastener that falls at the place where the new box must be positioned.

Gouging Out a Fastener

Using his knife, Boucher digs away the mortar covering the existing screw and washer that holds the Kerdi-Board to the wall stud.

Backing Out

Boucher removes the screw from the existing washer.

Removing the Fastener Washer

Boucher pulls the washer away from the wall.

Making a Hole

Boucher cuts a small triangular opening into the face of the wall where the box opening must be placed, to give himself a handhold on the piece of Kerdi-Board to be removed.

Making the Opening

Boucher pulls the cut-out piece away from the wall.

Dealing with Insulation

The wall between the shower and the adjoining bedroom has been soundproofed with rock wool insulation, which needs to come out.

Fitting the Recess Box

Boucher places the box in the opening temporarily. He still has to cut out the opening for another box right next to this one.

Tracing Another Outline

Boucher lays another recess box onto the wall next to the first one, and traces its outline onto the wall. He will now repeat the step of cutting out the opening.

Creating the Opening

Boucher removes the section of Kerdi-Board from the location where the second box will be installed.

The Wire

This box installation is complicated by the presence of a bedside lighting receptacle for the next-door bedroom, which can't be relocated. Fortunately, the 2x6 wall framing allows enough depth to hold both the recess box and the wiring box.

Hacking Back

To make room for his shower recess box, Boucher has to chisel away a piece of the scabbed-on 2x4 that the electricians used to attach their wiring box.

Fein Adjustments

Because the space is quite tight, Boucher has to carefully trim away the edges of the block with a Fein Multimaster.

Replacing the Sound-Control Batt

To preserve at least some of the soundproofing effect, Boucher replaces two inches of rock wool in the cavity.

Ready to Fasten

Boucher sets fastener washers into the seams where the recess boxes meet over the wall studs.

A Positive Connection

Boucher screws the washers down onto the Kerdi-Board to fasten the box firmly to the framing.

Cutting the Membrane

Boucher cuts a square of Kerdi membrane from a 100-foot by 1-meter roll of the material. He will apply this piece over the entire assembly of two recess boxes, then cut out for the box face openings.

Applying Mortar

Boucher works unmodified cement mortar into the flocked face of the Kerdi-Board boxes and the surrounding wall.

Tooling the Mortar

Using a Kerdi trowel with quarter-inch teeth, Boucher applies a measured amount of mortar to the wall where the membrane will be set.

Laying in the Membrane

Boucher lays his pre-cut piece of Kerdi membrane over the two boxes, completely covering the mortared joints.

Making Firm Contact

Boucher uses a six-inch drywall knife with the corners ground down to press the membrane into the mortar. He can see well enough through the membrane to visually check that the quarter-inch grooves in the mortar have been fully smoothed down, indicating a full mortar bond with the membrane.

Cutting Away the Openings

Boucher cuts out the openings with his knife (a task that is easiest before the mortar has set).

Ready for Tile

The completed pair of recess boxes. As soon as the mortar cures, this assembly will be waterproof, ready to serve as a sound backing for ceramic tile.

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