Fixit: Upgrading older sprinkler systems

Q What's the life expectancy of in-ground water sprinklers? We bought an 11-year-old house and some of the sprinklers don't come on, others spray this way and that. The bottom line is, there is no complete coverage and it even comes on when it's raining. Do we need a new one or should we try to fix it?

A Usually sprinklers need replacing at about five years, even if they've been properly maintained. (Sprinklers in our cold climate are susceptible to damage from winterization and freezing conditions.)

Valves can make it much longer but need at least a diaphragm and/or solenoid change to keep them humming.

Timers last the longest. However, regulations have changed in the last few years and many old timers no longer comply with water restrictions. Homeowners must then turn the system on and off manually rather than programming it properly. If the controller is older than five years, upgrade it.

The largest water savings comes from the sprinklers themselves when they provide water where it is needed. The next biggest saver is in the timer programming, which lets the system apply water when it is needed. Adding a rain sensor that automatically shuts off the irrigation system when it's raining saves water, and so does drip irrigation for non-grass areas.

You can hire out this upgrade work, or do it yourself. The easiest modification is to upgrade the sprinklers, timer and add a rain sensor. Sprinkler manufacturers may offer help for do-it-yourselfers. The Toro Co., for example, has you complete a short questionnaire and draw a map of the property indicating where the sprinklers, valves and timers are located. Toro reviews the plan and recommends upgrades retaining as much as possible of the existing system, buried pipes and working components. (For more information, go to www.torodesign.com, or your local Home Depot.)

Laura P. Lopez, The Toro Co.