Step 5 · Run the Hot and Cold Water Supply Lines
Using a drill and a 3/4-inch bit, drill holes through the studs from your hot and cold water main lines to the marked locations for the vanity supplies. Run a red 1/2-inch PEX tube for the hot supply and a blue 1/2-inch PEX tube for the cold supply through these holes. Leave several extra feet of tubing at both ends for flexibility. Secure the PEX tubing to the studs every 16-24 inches using PEX clamps or talons to prevent movement and noise.