Step 6 · Connect Drain to Waste Line
Access the plumbing area from below or through the access panel. You will now connect the tub's drain assembly to the house's waste line. This typically involves installing a P-trap. Dry-fit all the PVC pipe and fittings first. Connect the P-trap to the vertical tailpiece coming down from the tub's overflow tee. Then, connect the other end of the P-trap to the sanitary tee in the main waste line. Ensure there is a downward slope of 1/4 inch per foot from the tub to the main drain to ensure proper flow. Once you have confirmed the fit, disassemble the pieces. Apply PVC primer (usually purple) to the outside of the pipes and the inside of the fittings you are connecting. Immediately follow with a layer of PVC cement. Push the pipe firmly into the fitting, giving it a quarter-turn twist to spread the cement. Hold the joint together for at least 30 seconds to allow the solvent weld to set.