Connecting your lawn irrigation system to the plumbing system in your house is one of the final steps of installation. The water for your lawn irrigation system has to come from somewhere, so you need to hook your system to the house water supply.
Tapping into the water supply is one part of the installation that you should really get help on from a professional installer or plumber. Making a mistake with your plumbing system can be expensive when you have to call in the professionals to fix it.
First, turn off the main water supply to the house unless you want to have a huge gigantic gusher of a mess. The kids may like it, but you won’t.
The following list shows three ways to tap into the water supply:
Tap the outside faucet. Unscrew the outside faucet and install a 1-inch galvanized or copper tee fitting facing down. Screw the faucet back on to the tee. Below the tee, install a shutoff valve and then run pipe to the manifold and your irrigation system. This is probably the least complicated junction.
Tapping the main line. Cut a section out of your main line and install a compression tee fitting. Run the pipe a few inches away and install a shutoff valve. Then run pipe to your manifold.
Tapping the basement water meter. Just past the water meter, cut into the line and install a compression tee. From there, run a short line and install a shutoff valve. Run pipe up to the trench level outside and drill a hole through the basement wall. Run pipe out to the manifold.
The manifold is a grouping of control valves that connects the water source to the system and controls the flow of water to each circuit. Following your manufacturer’s instructions, attach the various pipes to the control valves at the manifold by using pipe tape (white tape that you wrap around the treads to prevent the connection from leaking). Attach the pipes carefully — not so tight that you damage the threads and cause the pipes to leak.
After you have the entire irrigation system attached to the manifold and the main water line, you’re heading down the stretch to the finish line.
Attach the risers.
Cut the pipe at each spot where a riser is to go and install a tee fitting. Install the riser, making sure that the sprinkler head will be at or just above soil level. If you’ll be planting sod, the heads need to be an inch or so higher than soil level to accommodate the thickness of the sod. A number of flexible or adjustable risers make this connection easy.
Flush the system.
To do so, turn on the main water line and then the irrigation system and flush out the pipes for a few minutes. Sprinkler heads can clog very easily, and you want to eliminate all dirt in the lines. Turn off the water.
Bring on the sprinkler heads.
Screw the sprinkler heads on to the risers, making sure that they’re adjusted correctly and pointing in the right directions.
Install a controller or timing device (optional).
If you’re going to install a controller or timing device, now is the time. This electrical device should be in a protected place not far from your power source. A heated garage or basement is good. Be sure to run the electrical wires to connect the controller to the manifold in a waterproof pipe. The controller should be buried to protect it from rain and freezing weather.
Test your system.
If all the pipes and fittings are not leaking, you can backfill the trenches. If you installed the system in an existing lawn, replant the open soil with seed or sod. Otherwise, you’re ready to do some final leveling and plant your new lawn.