Step 6 · Run Water Supply Lines
With the framing in place, you can run the hot and cold water supply lines. Turn off the main water supply to the house and drain the system. Tap into the main hot and cold water lines (usually 3/4-inch) with tee fittings. From these tees, run new 1/2-inch PEX tubing to each fixture location. Red PEX is for hot, blue is for cold. PEX is flexible and can be snaked through studs and joists easily. For the shower, secure a drop-ear elbow to a wood block between the studs at the correct height for the shower arm. Run separate hot and cold lines to the shower valve location. For the sink and toilet, run the tubing to the stub-out location and secure it to the framing. Use a PEX crimp tool to attach PEX fittings and shut-off valves (angle stops). Install stud guards (nail plates) over the framing wherever pipes pass through to protect them from future drywall screws.