Installing Sprinklers - An Overview
A sprinkler system, or more correctly an irrigation system has four main components: valves, pipes, sprinklers (or emitters) and an automatic timer control. The valves regulate how much water flows through the pipes to the sprinklers. The timer control regulates which valve is opened, when and for how long. The standard material for pipes is PVC (polyvinyl chloride). There are many styles of sprinklers to suit different needs.
PVC pipe is the standard for residential irrigation. PVC is inexpensive, durable and easily handled. Galvanized steel pipe can be used, but it is more expensive and much more difficult to install. Irrigation pipes are buried under ground in trenches, typically 9 to 18 inches deep. You must check with your local water company and/or appropriate municipal authority for information on building codes or required permits to install an underground sprinkler system. Furthermore, you must check with the local utility company before you begin digging. Serious injury or death can result from digging where buried electrical cables or gas lines exist.
Because most homes don't have enough water pressure to water everything at once, a sprinkler system is divided into zones. Another reason to do this is that different parts of your yard need different amounts of water. Your lawn needs more water than your cactus garden, so they should be in different zones. You can include separate areas of your yard into the same zone if you like. For instance, you may have two separate lawn areas that require the same amount of watering time. These two areas can be in the same zone or in two separate zones; whichever better serves your needs. Each zone is controlled by one valve. You can have as many valves as you need; however your timer control must have a provide a control circuit for each valve.
When planning a sprinkler system, you should group vegetation by how much and how frequently it needs to be watered. If you have sunny flower beds and shaded beds, they will probably need to be treated separately. This can be done by placing them into separate zones. Another way to do this is with drip irrigation. Drip irrigation uses sprinklers that allow precise watering. The emitters, bubblers and misters used in drip irrigation are rated in Gallons Per Minute (GPM) of water flow. You can mix high flow and low flow irrigation equipment all in the same watering zone.
Each zone will have one valve controlling one or more sprinkler heads. Sprinkler heads come in a wide variety of coverage patterns. You can select an assortment of coverage patterns to cover the entire zone. Add together the flow rate of the heads to be used in the zone. If they exceed the flow rate of the water supply, you will have to divide up the zone so that there is adequate pressure for the heads to be used.
Some manufacturers and home centers offer free design services to layout your sprinkler system. Take advantage of this service, it will save you time and help you to avoid costly mistakes.