DIY Underground Sprinkler System

Draw a plan on graph paper showing the location of the house, any sheds or garages and landscape features. Draw your map to scale. Determine how many sprinklers you'll need and their placement throughout the yard to ensure even water coverage. Break the yard up into zones and incorporate three to five sprinklers per zone. Perform some fine-tuning of zone coverage after installation to accommodate for any errors in head planning.

Hire a professional plumber to check your water pressure capability to handle a sprinkler system, install a water service line into the home's plumbing and attach a sprinkler anti-siphon valve outside the house. This keeps the system clean and allows for easy shutoff in case of an emergency.

Dig a hole in the ground for the valve manifold box approximately 3 feet from the anti-siphon valve location. Place the box in the hole with the main water intake line facing the anti-siphon valve. Run a PVC feed line from the valve to the intake of the manifold. Connect the line and tighten the clamps securely.

Mark the yard with bright spray paint to indicate the planned location of sprinkler heads. Spray lines in the grass, running from the farthest sprinkler head location to the next proposed head and continue until all heads in a zone are linked. Spray a line from this zone to the manifold and then repeat this step for each subsequent zone.

Rent a power trencher from a tool company and dig 8-inch trenches in the yard, using the spray-painted lines as a guide. Trenchers make proper cuts even through dry soil. Trench all lines at one time to maximize the use of the trencher. Run 3/4 inch PVC pipe from the manifold, through the trenches and to the location of all the heads. Connect the ends of these feed lines to the manifold and crimp the connections tightly.

Cut the PVC pipe into sections with a hacksaw at the locations for the sprinkler heads. Attach T-connectors or angle joints to create the locations for the risers and sprinkler heads, and use PVC glue to make the joints. Allow the adhesive to set for 15 minutes before continuing.

Glue risers to the PVC junctions, facing upward from the feed line, and let each of these connections set for 15 minutes. Connect the desired threaded sprinkler head to the riser -- either jet or fan spray nozzles depending on how much water is needed -- and tighten them with an adjustable wrench.

Align the arrow on the sprinkler head so it faces in the direction of desired coverage when connecting. Backfill the trenches to cover the sprinkler lines and cover the manifold. Level the lowered heads even with the top of the soil to keep them hidden below the grass.

Install a sprinkler control box in a nearby shed or garage and near an electrical outlet. Run a control wire from the manifold box to the control box and connect the line according to the manufacturer's wiring instructions.

Place the lid onto the manifold box and lock it with the restraining clips. If covering the box with dirt and sod, mark the location with a stake, rock or other item to make it easy to locate if necessary.

Turn on the main water supply and check for proper operation. Adjust the sprinkler heads so the yard gets even coverage in all areas.