Step 6 · Connect Water Supply and Drain Lines

This is the step most people slow down on. Take it one move at a time — there’s no rush, and you can rewind the clip as many times as you need.

Now, connect the plumbing. Attach the flexible water supply lines from the faucet inlets down to the corresponding hot and cold shutoff valves. Hand-tighten the nuts, then use a wrench to give them an additional quarter- to half-turn. Do not overtighten. Next, assemble the P-trap. Connect the tailpiece extension to the bottom of the sink's drain assembly if needed. Attach the P-trap to the tailpiece and the drain stub-out in the wall. The slip nuts on the P-trap are designed to be hand-tightened only. Ensure all gaskets are properly seated before tightening.