Underground Sprinkler Installation

Check for underground utilities before digging or any excavation. Your house plans should give you a basic idea, or call the local utility company for assistance in marking gas, water or electric lines underground.

Map out and measure the desired locations for the sprinklers.

Check water pressure with an appropriate water gauge. Purchase one at a local hardware store. Or find your water pressure by contacting your local municipality.

Check water meter size. If you live in and use the local municipal water system, you will find the water meter size on the meter outside for your property. If you can't find it, look on your utility bill or call your local water provider.

Wrap a piece of string around your water service pipe once, then measuring the length to note your water service line size.

Measure the water flow rate by timing how long it takes to fill a gallon container to a measurable level. Divide the filled volume by the measured time and convert to gallons per minute or gallons per hour.

Buy the correct sprinkler system parts based on the measurements taken in steps 3 to 6.

Lay out PVC pipe in the locations that will run to each sprinkler head.

Slot the grass by entering the shovel 6 to 8 inches in the ground and then pulling back, do the same thing in the opposite direction. Continue this process along each layout line for the PVC pipe.

Return to the spigot where the PVC pipe will start, leaving 2 feet of extra pipe to run up to join the spigot. Run the PVC directly into the slotted areas, using your shovel handlebar to assist you in making a tight fit.

Cut the pipe leaving an extra 3 inches for connection.

Read the detailed installation instructions of the sprinkler heads. The head assembly will consist of sprinkler head, the riser and the NPT tee.

Wrap the Teflon tape around the ½-inch male end of the riser before screwing it into the female NPT tee.

Dig a large enough area where you have planned to put the sprinkler head, leaving enough room for the head assembly.

Place the assembly in the dug out area and position it toward the lawn area to be watered.

Cut the PVC so it fits and runs up the length of the head assembly; now connect it per the manufacturer instructions of the sprinkler head.

Return to the spigot and install a splitter, timer and spigot fitting. Check all valves are closed, and apply the Teflon tape to the spigot threads and tightly screw on the splitter.

Apply a layer of Teflon tape to the timer threads and screw on tightly to the timer.

Connect PVC pipe to the timer with Teflon tape and PVC glue. Let dry.

Loop with the Flex PVC pipe into a small circle, but do not kink it as this will restrict water flow. This loop will provide any back flow of dirty yard water into the house's drinking water supply.

Cover the PVC pipes by pushing the slotted grass back over the pipe. Save this step till the very end of your project as it could be a hassle to dig back up and rebury pipes if you need to make any adjustments.