How to Tap Into a Water Line. If you need a source of water for the sink or the refrigerator's icemaker or water dispenser, there are a variety of ways to tap into an existing water line. Copper lines require a special set of tools to tap the water line; plastic pipes are simpler and a bit easier to work with. Use these steps to tap into a water line.
Determine where the water line is located. Most water lines run through the basement or sub-flooring. Consult with the homebuilder if possible to better locate the water lines.
Look at the material the water line is made of to determine the line tapping kit best suited for the project. Copper water lines require a metal piercing saddle kit, while PVC or plastic piping uses a small needle to puncture the tubing.
Buy a water line tapping kit at any hardware or home improvement store, such as Lowe's or Home Depot. Talk with the salesperson about the project and have them point out the correct materials.
Turn off all water to the house. If this is not possible, simply locate the water line's cut off valve nearest the project location. Many are located just under the sink or where the water line enters the home.
Situate the water line tapping saddle onto the pipe and clamp into place. Begin rotating the tap screw until it pierces the piping. Slowly unscrew the tapping screw and remove saddle device.
Affix the new hose or water line over the pierced hole. Secure using the water line tapping kit's materials making certain that a watertight seal exists at the tapping location.
Place a towel or pan under the water line being tapped. This will absorb much of the water that will undoubtedly spill from the pierced hole. Use Teflon tape or plumber's putty to secure the junction and to minimize future leaks at that location.
Never force the tapping screw. Failure to heed this warning may result in a piercing that continues through the entire pipe. This will mean a new pipe section will have to be placed.