Installing A Sprinkler System For Your Lawn

The layout

After drawing the layout of your property, divide the area you want to irrigate into zones based on the watering requirements of the plants in the area. Each zone will be controlled by a valve that regulates water flow to the sprinkler heads in that area. Because sprinkler heads come in a variety of coverage sizes and flow rates, you'll want to find out what's available before planning. Some garden centers offer free assistance with sprinkler system design and can advise you on the amount, size, and type of pipes, valves and sprinkler heads you'll need. A little professional advice now can save you from a lot of trouble and expense later.

Prepare the area and the material

Mark the location of each sprinkler head and control valve with a stake. Then run a length of string between the stakes to mark the placement of the pipe run. At this point, you can measure the pipes and use a hacksaw or a tubing cutter to cut all the pipes you'll need at once or wait and cut each pipe as you need it.

Tap into the water supply

Where you attach the T-fitting to tap into your water supply will differ depending on where your pipes are located. First, shut off the water at the stop valve. The T-fitting can now be attached behind the hose faucet, past the outside water meter on the main water line to your house, or past the meter in the basement. Once the T-fitting is in place, attach the close nipple followed by the faucet.

Attach the anti-siphon valve

Keep in mind that to do its job the anti-siphon valve has to be installed at least 6 inches higher than the highest sprinkler head. Also, for easy maintenance, space the valves at least 3 inches apart. To attach the anti-siphon valve, start by cutting two short pieces of pipe and attaching a male adapter to one end of each. Thick Teflon plumbers' tape should be wrapped 3 to 5 times around the threads of the adapters. Next, screw one of the pipes into the T-fitting. Using a slip elbow, attach the other pipe to this pipe. On the other male adapter, attach the anti-siphon valve.

Install the main shut off valve

Because this valve is infrequently used, a gate valve is suitable, but a ball valve or disk valve will last longer. Cut another short piece of pipe and attach male adapters on both ends, wrapping the threads of the adapters with Teflon tape. Attach one end of this pipe to the anti-siphon valve and the shut-off valve to the other end.

Dig the trenches

At the supply pipe, start the trench 9 to 12 inches deep. As you continue digging along the pipe run, the trench should slope deeper 1/4 inch for every 6 feet to help the pipes drain. Continue with the slope wherever you branch. To tunnel under a sidewalk or wall, dig away as much soil as possible and use a pipe closed with a plastic cap or duct tape to push a hole through the soil. Dig out any loose dirt from the bottoms of the trenches to keep them level. For better drainage, line the trenches with an inch of gravel or sand.

Attach the shut-off valve to the pipe run

Cut a length of pipe long enough to reach from the end of the shut-off valve to the bottom of the trench. Attach a male adapter to one end, wrapping Teflon plumbers' tape around the threads, then attach an elbow to the begin the pipe run.

Install the pipe run

To build the pipe run, connect the pipes with solvent glue and use slip elbows to turn corners and T-fittings or slip crosses to make branches. Wherever you plan to place a sprinkler head, install a T-fitting, using a carpenter's square to be sure the fitting is level with the ground. For proper drainage, drain valves should be placed at the end of each section of the run.

Attach the risers and sprinkler heads

Once the solvent glue has cured, you can flush out the system and attach the risers to the T-fittings. Depending on the type of glue, this may take up to twenty-four hours. To check for leaks, turn on the water and open the valves one at a time to flush out each zone separately. Once the system is flushed, you can attach the sprinkler heads. Cut the risers and glue a male adapter to one end, adding Teflon plumbers' tape to the threads. To give each riser extra support, drive a stake into the ground beside it and wire the riser to the stake. When the risers are in place and the solvent glue has dried, the sprinkler heads can be attached.

Install the timer

The electronic timer or controller is what allows you to water one zone at a time to avoid straining your home's water supply. Each timer will come with a set of installation instructions, but the basics are similar for most types of timers. To install the timer, attach it to the wall with screws and connect it to the transformer. Next, run low-voltage wires to the control valves, burying the wires underground where possible. The gauge of wire you'll need will depend on the size of the sprinkler system.

Test the system

After waiting twenty-four hours for the solvent on the pipes to cure, open one valve at a time to test each zone in the system. This will allow you to see any leaks and give you a chance to repair them. Once the whole system works, fill in the trenches with the dirt you removed, being careful not to place any rocks directly onto the pipes, and replace the sod.

Installing an underground sprinkler system for your lawn will both improve the condition of the lawn and save you from having to drag hoses around all summer. To make sure the installation goes as smoothly as possible, start with some advice from a professional landscaper at your local garden center. Once you have a clear understanding of how to install the system, the work should progress without any difficulty.