Steps 5-8 To establish the exact horizontal length of the supply pipes that protrude from the wall, look at the markings on the black plastic spacers covering the faucet stems. The outer mark should align with the surface of the finished shower wall. Using these marks, cut a length of pipe long enough to leave the threads of a male adapter protruding 3/8 in. from the wall. Solder this assembly together with a male adapter on each end. Wrap the threads of the adapters with Teflon tape and tighten them onto the valve with an adjustable wrench (photo 5). Set the faucet, fitted with pipe stubs, into the wall with the spacers extending through the wall openings. Match the water-supply pipes with the pipe stubs and mark each cut with a pencil. Remove the faucet, and cut the pipes and stubs to fit. Sand each pipe end with emery cloth, then set the faucet back in place. Brush flux onto the pipe ends and solder the connections with couplings and 45- and 90-degree elbows (photo 6). Warning: The flame from the torch can scorch and even set fire to combustible surfaces. You should protect the work area with a double thickness of sheet metal or a flame-shield fabric, which is available at plumbing-supply shops. After soldering the joints, check the marks on the plastic spacers. Reposition the valve assembly, if necessary, then slip a 1 X 2 support block behind the valve pipes (if one isn't already in place) and screw it to the stud at each end. Secure the pipes to the 1 X 2 with copper straps fastened with 1 1/2-in. screws. Finally, turn the water on and check for leaks. To trim out the faucet, begin by removing the black plastic spacers from the control stems. Then thread the tub spout onto its male adapter. Mount the volume trim flange and handle onto the left-hand control stem and connect the temperature trim flange and handle onto the right-hand stem. Now test the valve by turning on the water to its highest temperature setting. If the water feels too hot, turn it off, remove the handle and locate the nylon rotational limit stop on the stem. It's marked with two arrows. Rotate the stop several notches, as shown in the manufacturer's instructions, and replace the handle. Retest the system and readjust the limit stop if necessary. To repair the access hole cut in the wall, screw 1 X 2s between the wall studs, then screw the piece of drywall you removed earlier back in place. Conceal the patch with paper tape and three or four coats of joint compound (photo 7). Finally, on the shower side, apply a thin bead of silicone caulk around both trim plates and the tub spout (photo 8). Allow the silicone to cure overnight before using the tub or shower. You can now shower comfortably knowing that the only shock you might experience is when you actually sing on key.