How to Install Sprinklers Correctly

DIY Lawn Sprinkler InstallationLearning how to install sprinklers is a great project if you have a town house or other property with a smaller lawn, because this is a project that can be completed with a few weekends of research and a few weekends of construction.

What you Need to get Started

The first thing to do is to draw up a plan with the measurements of all the pipes and how they will be laid out. This includes the main pipe, lateral pipes, and risers for the sprinklers.

Keep in mind that sprinkler heads need to be at least six inches away from the side walk and eighteen inches away from the house.

Count up the number of sprinkler heads and connecters you need, the total length of piping, and the amount of wire required if the system is automatic.

You will also need items like PVC cement, wire splice, waterproofing kits, thread sealant, and any installation tools necessary for the project.

Laying Out the System

Once you have all of your materials and tools together, you are ready to lay out your sprinkler system. Start by marking each of the sprinkler head locations and place a stake where you want each sprinkler head to go. Mark the trenches for the pipe on the ground with chalk or white paint.

If you are fortunate, a water stub-out was built into the house for the sprinkler system as part of the original construction. All you need to do is connect your piping to the stub-out and then install a backflow preventer and an emergency shut-off valve. If there is no water-stub, you will most likely be cutting and tapping into the water supply line leading into the house.

Digging the Trenches

A day or two before you begin digging the trenches, water the soil thoroughly to soften it, but don’t over-water. When you start trenching, periodically water down the area to keep it moist so the digging is easier.

Remember, all plastic mainline pipe must be buried at least 18" below the soil surface. Lateral trenches for home irrigation systems can usually be installed about 10" below the soil surface.

Installing the Pipe

The easiest way to install the pipe is to start at the main water source and work out to the valves, continuing to the end of each lateral pipe where the risers and sprinklers will be installed.

Cut and assemble the pipe outside of the trench and then lower the assembled sections into the trench as you move along. Try to avoid getting dirt into the pipe as you assemble it.

Next, install the sprinkler risers and the sprinkler heads to pipes. If you have an automatic system, don't forget to install the control wire for the valves while the trenches are open. Also, make sure to water-proof the wire splices and use pipes to protect them from damage.

Once the pipes are assembled, you can start putting the dirt back into the trenches, but only fill the trenches half-full with dirt. Open the emergency shut-off valve to the full and open position and let the water run for at least 5 minutes to test and flush the system. This is the time to make sure everything is working before you replace all of the dirt.

When the flushing is complete, finish filling the trenches. Compact the dirt around the trenches by stomping on it.

After about a week of testing and running the sprinklers, you can finish the project with sodding, bushes or other plants that will enjoy your new sprinkler system.

Sprinkler Photo by Phu "Son" Nguyen