How to Install a Faucet & Drain in a Pegasus Granite Countertop With Undermount Sink

Turn off the hot and cold water to the sink. The valve is usually located under the sink or near the toilet, if you are working in the bathroom. If you can't find the valve, you can shut off the main water valve, which is usually located in the garage, basement or outside on the lawn by your water meter.

Apply plumber's putty around the holes in the granite if your faucet doesn't have a built-in rubber seal. Use a generous amount of plumber's putty.

Feed the faucet pieces through the appropriate holes and adjust the faucet so it is straight and flat on the granite.

Roll the nuts up the faucet pipes to secure the faucet in position. Avoid tightening the nuts with a wrench — hand tighten only.

Connect the faucet to the supply lines with flexible, braided, stainless steel covering. Use supply lines that are just long enough to connect the pipe and faucet. Attach the supply lines to the water supply first, tightening the bolt with a wrench.

Flush the supply lines. Simply hold the open end over a bucket and turning on the water supply. This removes any impurities that could clog your faucet. Turn the water off after letting it run for a minute.

Install the vegetable sprayer, if you have one, putting plumber's putty around the appropriate hole and pressing the decorative ring into the hole. Tighten the washer under the counter around the bottom of the decorative ring. Insert the hose through the decorative ring so it hangs into the cabinet below. Apply thread joint compound to the threaded supply tube and tighten the end of the vegetable spray hose to the supply tube.

Cover the clean, dry drain holes with a ring of plumber's putty. Push the putty into position.

Press the strainer down into the hole and push it down tight. The putty will squeeze out. Wipe the putty away from the top and bottom of the sink with your finger.

Place the rubber ring on the metal washer and put it over the strainer bottom, underneath the sink. Secure it in position with the tightening nut. Tighten it with a wrench. Have an assistant hold the strainer in position as you tighten the nut with needle-nosed pliers.

Screw the trap adapter onto the end of the sink drain's tailpipe. Fit PVC pipe to the end to the trap adapter so an elbow joint is below the tailpipe. The fit will vary, depending on how the pipes align under your sink. Create the most direct route to the drain as possible.

Connect the drain pieces, first painting a PVC primer onto the threads and letting it dry. Apply PVC cement on top of the primer and connect the pipes, tightening the pieces with your hands. Do not use the drain until the cement has dried according the to the manufacturer's specifications.