Step 4 · Install Drain Line
This is a critical plumbing step. Locate the 2-inch PVC vertical drain stack you plan to connect to. Use a reciprocating saw or PVC pipe cutter to remove a section of the pipe where your new line will connect. Clean the cut ends. Apply PVC primer to the inside of a 2-inch PVC sanitary tee fitting and the outside of the pipe ends. Then, apply PVC cement over the primer and quickly push the pipe ends into the fitting with a quarter-turn motion to ensure a good seal. Run a new 2-inch PVC pipe from the sanitary tee to the outlet box location. Ensure the pipe has a constant downward slope of at least 1/4 inch for every foot of horizontal run to ensure proper drainage. You will likely need to install a P-trap assembly near the box connection point to block sewer gases, as per code.