Installing a Sprinkler System on Large Properties

If you’ve got a spacious yard and are getting tired of moving the lawn sprinkler every few days in the hot weather, it may be time to install an underground sprinkler system. The system can ensure that your lawn is watered evenly, and will keep your grass green and healthy all year round. It’s best to use professional tools and methods to keep the sprinklers functioning, and you can even program the sprinklers to start and stop when you want. Here are a few important things you should know.


Start Planning

Before you install the sprinkler system or start digging in your lawn, contact your utility company. A company representative will come to your home and mark the site of all the buried cables. You should also use a tape measure to calculate the length and width of your yard. Planning for your sprinkler system also means measuring the water pressure to determine how much ground your sprinkler should cover. Mark your lawn with small flags to indicate where the sprinklers will go. It is also best to be aware of plumbing codes in your area before you start working and to check and see if a building permit is necessary for your sprinkler project.

Once you install the sprinklers, make sure that the spray from one sprinkler head makes contact with the other sprinkler heads, so that your lawn will not have any dry spots.

Water Pressure

You’ll need a gauge to determine your exact water pressure. Measure the pressure at an outdoor faucet with a gauge that you can purchase at your local home repair store. You can also use a bucket that holds up to 5 gallons to determine how much water is delivered per minute. Send these details to your sprinkler manufacturer so that you will get the right sprinkler devices for your lawn. You should also send a scale drawing of your yard so the manufacturer can provide a sprinkler system that will adequately water the entire lawn.

The sprinkler manufacturer will send you a layout of the sprinkler system, along with a list of the materials you will need. They may also send you a fee scale, so you’ll know exactly how much you’ll have to pay for the entire system. The layout will show your lawn, divided into zones, with each of these zones being controlled by a valve.

Water Line Accessibility

The easiest way to ensure that there is water for your irrigation system is to connect the sprinkler system to a spigot that you already have. Or, you can tap into the main water service line on your property. Both of these methods require you to have an anti-siphon valve installed. This valve stops brackish water, fertilizers, and chemicals from your lawn maintenance routine from getting into the main water supply.

Digging the Trench

The trench should be 6 to 8 inches deep, with sides that slope at a 45-degree angle. When you are digging the trench, separate the soil from the sod, so it will be easier to patch and fill the trench later. You can make this part of the process go faster by renting a trenching device (usually called a vibratory plow) from your local home repair store.

Valve Manifold Installation

To install the valve manifold, dig a hole that is a little larger than the manifold box. Gently place the box in the hole and attach one end of the manifold assembly to the main water supply. Be sure that the clamps are securely connected.

Running the PVC Pipe

On the other end of the valve manifold, connect ¾ inches of PVC pipe, and keep spreading the pipe along the main trench. You may also want to use tee connectors for the pipes that run off the main water line. Use 90-degree connectors to attach risers at each of the places where you have pitched a small marker flag. When you glue sections together, apply a thin, smooth strip of adhesive. 

If you live in a warm climate, run the whole sprinkler system in PVC pipe. PVC pipes are flexible and able to withstand several cycles of freezing and thawing. If you are digging your entire sprinkler system by hand, dig the main runs before the branch lines.

Remember that every sprinkler system needs a back-flow preventer so that the sprinkler water won’t contaminate your potable water supply. You can choose a back-flow preventer that is surface level, which has to be installed about 12 inches above your lawn’s highest point. If you have a basement, you can put the back-flow preventer there to drain your water system at the back-flow point every winter.

Sprinkler Head Installation

The sprinkler heads you select for your system should be based on your lawn’s irrigation needs. Before you attach the sprinkler heads, flush water through your sprinkler system to clean out impurities and debris. The sprinkler heads should be installed on the risers, and you should make sure the heads are level with the soil in your lawn. Use sod and dirt to fill in the holes and trenches.

Controller Installation

Finally, a timer controller is an essential tool for your sprinkler system, since it controls how much water your grass is getting, as well as how much time your lawn is being watered for. Use the manufacturer’s instructions to connect the controller wires. The final connection of the timer controller should be at the main water service line. After you’ve completed installation, turn the system on to make sure it’s working properly. You can make small adjustments to the sprinkler heads if necessary to ensure that your entire lawn is being covered evenly once the system is turned off.

Continue to consult professionals to keep your lawn looking its best, even after you’ve completed your sprinkler system installation. A lawn specialist can let you know if you should adjust the watering time for your yard based on the type of grass you have. Continue to have your pipes inspected while the sprinkler system is installed to make sure there are no leaks or cracks.