How to Install a Sprinkler System With Poly Pipe

Draw a scale drawing of your lawn. Indicate where the house and other permanent fixtures are located. Indicate where to hang the control box near an outdoor electrical outlet. The control box also needs to be near the water source for the poly pipe sprinkler system. The valve box should also be close to the water source. Indicate on your drawing where you plan to install the PVC pipes as well as the sprinkler heads.

Hire a plumber to create a connection to supply water from the house’s main water line. Add a backflow preventer and a pressure reducer to this valve. Most cities require that a licensed plumber perform this task. Check with the local building codes office; you might be able to do it yourself if you have plumbing skills.

Dig a short trench from where the water supply line emerges from the house to where you plan to set the valve box. This trench needs to be below the frost line.

Connect the water line to the valve receptacle in the valve box using a piece of PVC pipe. Smear pipe glue around the ends of the PVC pipe, using the applicator in the glue, before inserting the pipe into the valve connector in the valve box. Twist the pipe one-quarter turn to seat the glue. Connect the other end of the water line pipe to the house’s water line, using fittings that match the water supply pipe from the house.

Dig the remaining trenches for the poly pipe following the diagram you completed in Step 1. If you have a lot of digging to do, rent a trencher to do the job.

Lay the pipe into the trenches. Connect the pieces of pipe with the appropriate connectors fastened with pipe glue. For added protection, slide a pipe clamp over the end of each pipe. Tighten it with a screwdriver. Attach the pipes to the valves in the valve box. Do not attach the sprinklers at this time.

Hang the control box near the electrical outlet. Run the electrical wiring from the valve box to the control box. Match black wires to black wires, white to white, red to red and green to green. Plug the control box in to see whether the valves are operational.

Turn water on to the lawn sprinkler system to flush debris from the poly pipe. Turn the water back off and unplug the control box.

Install the risers for the sprinkler heads on the ends of the poly pipe using the pipe glue. Adjust the risers so they all are pointing up. Attach the sprinkler heads to the risers and set the sprinkler heads to the desired spray pattern.

Backfill all the dirt in the trenches over the poly pipe. Tamp it down with a hand tamper. Cover the valve box with its cover to protect the valves.

Turn the water back on to the system. Plug the control box in to its outlet. Set the control box to the desired water times.