Sprinkler system isn't hard to install

Q Can you tell me about automatic lawn sprinkler systems? I'm thinking of investing in one, but I hate to see systems watering when it's raining or has just rained. Is there one that doesn't do that? How much do they cost?

A An automatic lawn sprinkler system is an underground system of pipes and spray heads with a controller that the homeowner programs for automatic watering.

Many contractors can install a system for you (check yellow-page directories under "irrigation"), but you can save a lot of money doing it yourself.

"It's not difficult," said Randy Hall, product manager at Rain Bird, a manufacturer of automatic sprinkler systems and components. "Cutting and fitting together the pieces is easy, like building with Lincoln Logs."

Most of the effort is in burying the lines. Do it-yourself information is available online or at stores where you buy components and systems, such as Menards and Lowe's. Trenching is the most demanding part of the job, said Hall, but you can rent equipment that makes the job easier.

In either case, the first step is design. Yards consist of areas with varying plant materials -- grass, trees, shrubs, planting beds -- with different watering needs. A contractor will create a design that divides the yard into zones of like materials. (Do-it-yourselfers can use Rain Bird's free online design service. Go to www.rainbird.com. Click on "sprinkler design service" near the bottom of the page.)

An automatic sprinkler system consists of:

• Spray heads, typically drip or, the most popular, pop up. Buried flush with the ground, the latter type will pop up about 4 inches when water pressure is applied. They produce full, half or quarter patterns of spray, or they rotate.

• Underground piping, either PVC (white rigid) or poly (black flexible), supplies the spray heads with water. One type isn't necessarily better than the other, according to Hall.

• Valves on the pipes open or close off water to the spray heads.

• A controller operates the valves, determining where to water, when and how much. Pay attention to the controller you get. Easy, quick and flexible programming ability is important. You need to be able to easily adapt the system to fit changing needs, such as when water use is restricted.

An easy-to-use controller lets you conserve water, too, said Hall. Set up the system for your best guess at water needs. If your landscape is thriving, dial back the water supply by 10 percent. To keep from wasting water, repeat this until you notice stress in plants, then add back the last 10 percent.

• A rain sensor prevents watering your lawn during or right after nature provides it. Attached to the eaves of your house or a similar location, a sensor sends a signal when it rains that keeps the system from watering.

A typical installation has six watering zones and can cost about $3,000, according to Carefree Lawn Irrigation in Minneapolis.

In addition to Rain Bird, Toro (www.toro.com/sprinklers), Irritrol (www.irritrol.com) and Hunter Systems (www.hunterindustries.com) offer automatic lawn sprinkler systems and components.

Send your questions to Fixit in care of the Star Tribune, 425 Portland Av. S., Minneapolis, MN 55488, or call 612-673-7032, or e-mail fixit@startribune.com. Past columns are available at www.startribune.com/fixit. Sorry, Fixit cannot supply individual replies. Fixit appears daily in Source except on Friday.