Step 1: Cut the Shower Floor

When you are replacing a shower floor, it's a good idea to replace the P-trap while it is accessible.

Cut open the shower floor, giving yourself enough room to work around the drain.

Step 2: Measure and Cut the Plywood

Draw lines on the area you want to cut (Image 1), then make a plunge cut with a circular saw (Image 2). Cut along all four lines, then use a reciprocating saw to cut the piece in two (Image 3). Pry up the pieces (Image 4).

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    Image 1

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    Image 2

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    Image 3

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    Image 4

Step 3: Position the P-Trap

Use a reducer to transition from the existing 1.5" drain line to the 2" drain. Apply ABS glue to the pieces and press them firmly together (Image 1). Be sure to place the P-trap in the correct location for the drain (Image 2).

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    Image 1

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    Image 2

Step 4: Install New Plywood

Drop a new piece of plywood into place so you can measure the distance from the drain to the P-trap. Cut a piece of ABS to connect them.

Screw plywood to floor joists, then attach the drain.