Install an Outdoor Sprinkler

(From Fix It Up!, courtesy of

If you're tired of dragging hoses around whenever you want to water the lawn, it might be time to install an automatic sprinkler system. As Fix It Up! hosts Pat Simpson and Jodi Marks demonstrate, it takes some planning and elbow grease, but the results are well worth the effort.

A low-pressure micro-irrigation system can carry water to plants and ground cover. It keeps roots evenly moist while ground cover stays relatively dry. The system is inexpensive, easy to install and adaptable to many landscapes. For best results, use a system with a built-in timer to prevent your lawn from becoming too wet or too dry.

* Some of the variables you'll need to consider are your climate, soil type, wind conditions and your water flow rate and pressure. If you're unsure about your water supply, call your utility company for more information. Your meter capacity will determine the number of sprinkler heads you can install per zone in your irrigation system.

* Check with your building codes enforcement agency to make sure you follow the installation requirements for your area.

* Call your utility company before you begin digging. They'll help you locate any underground pipes or cables so you don't accidentally damage them.


sprinkler kit (includes PVC pipe, connectors, sprinkler heads and a timer)
gas-powered trenching machine
PVC primer and cement
PVC pipe cutter
measuring tape
safety glasses
work gloves


  1. Locate the supply pipe leading from the water meter to your house. You'll have to dig to access the pipe, so be careful not to damage it with your shovel. Measure the diameter of the pipe so you can be sure to purchase the proper size fittings (a common size is 3/4 inches).
  2. Draw a map of your lawn to help you in laying out your sprinkler system. Mark all potential obstacles such as the house, driveway, mailbox and flower beds. Then add the locations for the water meter, the sprinkler timer and the sprinkler manifold (figure A).

  3. Mark the placement of your sprinkler heads. Arrange the heads so that the spray from one head will barely overlap the spray from adjacent heads. Your sprinkler system supplier can help you determine how many sprinkler heads and circuits you'll need.

    * For convenience, place your manifold (the location where all the valves come together) near the main water line.

  4. When you've finished drawing the sprinkler system layout, transfer the measurements to your yard. Lay your PVC pipes along the supply lines, mark the manifold and valve locations, and place colored flags or other markers (included in the kit) at each sprinkler head location. To check the spacing of the sprinkler heads, cut a piece of string to the same length as the spray coverage and stretch it from flag to flag.
  5. Use a gas-powered trencher to dig a trench for the system (figure B). You can rent a trencher for about $150 to $200 per day. Some trenchers include a "vibratory plow," which digs a trench and places the PVC pipe at the same time; this feature minimizes damage to your lawn.

    * If your soil is rocky, fill your trenches with a shallow bed of sand before placing the pipes. This will prevent the pipes from resting directly on sharp rocks, which might cause them to break under pressure.

  6. Turn off the water supply at the meter.
  7. Use a PVC pipe cutter to remove a two-inch section from the pipe leading to your house.
  8. Clean both cut ends of the pipe and replace the section with a PVC T-fitting. Position the fitting so that the base of the "T" points upward, and glue the fitting in place with PVC cement.
  9. Attach a short piece of PVC pipe and a 90-degree elbow to bring the water supply to the desired height for your sprinkler system supply lines (figure C).
  10. Begin connecting the PVC sprinkler supply lines from the main water supply to the backflow preventer.

    * Some building codes require a backflow prevention device to be placed between the meter and the manifold. If you're installing a sprinkler system in an area where freezing is an issue, be sure to keep drainage in mind; you'll need to drain the system in the winter to prevent it from freezing and bursting your pipes.

    * If building codes don't require a backflow preventer, you should at least include an anti-siphon valve to prevent the water that enters your sprinkler system from backing up and entering your household water supply.

  11. Dig a hole for the backflow preventer. Pour a two-inch layer of gravel into the hole to allow adequate drainage. Place the valve cover in the hole and add additional gravel to bring the top of the cover flush with the lawn surface. When the cover is positioned properly, use PVC cement to attach the backflow preventer (figure D).
  12. Close both shutoff valves on the backflow preventer. Then turn on the water at the meter and open the valves to check for leaks and flush the system.
  13. After the system has been flushed, turn the backflow preventer valve off and run PVC pipes to the location you've selected for the manifold. Following the manufacturer's instructions, assemble the manifold using short pieces of PVC with T-fittings.
  14. Attach a threaded cap at the last T-fitting to allow for manual drainage.
  15. Attach timer valves to the manifold using PVC cement.
  16. Use PVC cement to attach the valve manifold and timer assembly to the main pipe (figure E).
  17. Turn on the water supply to check for leaks and flush the system.
  18. Turn off the water and begin connecting the sprinkler lines. Start at the manifold (figure F).
  19. Assemble all of the sprinkler risers, but don't attach the sprinkler heads yet. After all the connections are made, turn on the water at the shutoff valve to check for leaks and flush out any dirt and air. Use the timer valves to flush one zone at a time; make sure the water runs clear before moving to the next zone.
  20. When the system is thoroughly flushed, you can begin attaching the sprinkler heads. Begin by cutting the risers to the appropriate height based on the manufacturer's instructions.
  21. Attach a threaded coupling to the top of each riser.
  22. Plug each coupling with a threaded cap; leave a coupling unplugged at the end of the circuit so you can flush the system.
  23. After flushing the system again, remove the plug from each riser. Then wrap the threads with Teflon tape and attach the appropriate sprinkler head to each riser.
  24. Hold each riser to keep it vertical while an assistant fills in enough dirt to stabilize it.
  25. Test the system to make sure the sprinkler heads are positioned appropriately. The coverage from each sprinkler head should slightly overlap the coverage of the adjacent heads. You might need to move the heads or tweak the spray pattern for proper coverage. Make sure the system has no leaks before you begin filling the trenches.
  26. Fill the trenches with soil, stopping just short of the top of each trench. Use a tamping rod to pack soil tightly into each trench. Make sure the dirt goes under the pipe so there are no air pockets.
  27. Add a two-inch bed of gravel under the manifold to allow proper drainage.
  28. Fill in around the backflow preventer with gravel as well. This will keep rainwater from creating puddles inside.
  29. Place the sprinkler system timer in a dry location. If you have to place the timer outside, make sure it's in a weatherproof box.
  30. At the valve manifold, attach coated irrigation wiring (rated for underground burial) to each valve. Each valve has two wires: a circuit wire and a ground wire. Use wire nuts to connect the ground wires together. Then, following the manufacturer's instructions, connect the circuit wires to the terminal screws at the timer.
  31. Fill in any remaining areas with dirt, and bury the cable leading to the manifold.
  32. Connect the timer to a power supply, and test it to make sure it controls each zone properly. Then set the timer for automatic irrigation.

    * Set the timer to water your lawn early in the morning rather than at night. Nighttime watering can promote disease.