How to Make an Underground Water Sprinkler System

Contact your zoning board to determine whether you need a building permit to install an underground sprinkler system. Call your local utility companies. Have them check to see where underground pipes are in your yard. This ensures you do not dig into a gas line.

Place an empty bucket by the outdoor spigot to check the flow rate of water. Note how much time it takes to fill the bucket. Divide the size of the container by gallons to how many seconds it takes to fill the bucket. Multiply the number by 60. The total is the gallons by minute flow rate. Calculate your home's water pressure with a pressure gauge. Purchase a system that works best for the water flow rate and pressure.

Purchase PVC or polyethylene pipe. Layout the pipe on the grass in the desired sprinkler system pattern. Place markers in the lawn to plot out where you will dig the trenches. Create level trenches with the garden spade. Have the trench deep enough so pop-up sprinkler heads do not stick out the ground to become damaged by mower blades.

Assemble the pipes before laying them in the ground. Saw the pipe to length with the pipe cutter and file ragged edges. Clean fittings with a solvent primer. Place pipe cement or adhesive to the pipe. Fit it into the fitting and twist the pipe to spread the cement. Use clamps when connecting polyethylene pipes to fittings. Connect sprinkler heads according to the manufacturer instructions based on the type you purchased.

Connect the sprinkler system to your water supply. Attach a valve to the outdoor faucet. You can also connect to the main water line. Have the municipal water authority turn off the main service line to your house. Cut out a section of line. Place in a connection tee with a valve.