Securely mount the new single-handle valve body inside the wall. Most valves must be attached to a wood support block (a 2x4) running between the studs. Cut a piece of 2x4 to fit snugly between the studs and screw it into place. Position the new valve body so that its center aligns with the hole you cut, and crucially, at the correct depth. The valve instructions will include a plastic guard or guide showing the correct depth relative to the finished wall surface. Secure the valve to the 2x4 support with screws. Now, prepare the pipes. The old separate hot and cold lines that went to the side handles need to be capped off. Cut them back and install push-to-connect caps. You will then run new 1/2-inch copper pipe from the main hot and cold lines to the new valve's inlets. Use your tubing cutter to cut new pieces of copper pipe as needed to connect the existing hot, cold, and shower riser pipes to the new valve. Use a deburring tool on the inside and outside of every cut pipe end to ensure a smooth surface for a watertight seal.
Step 4/7
Install and Plumb New Valve2 min