The thought of installing an irrigation system may sound daunting to many people, but with a good knowledge of the equipment and logical planning it can be easily achieved. Although great savings in money can be made, the home installer should be prepared to spend time on the project to ensure its success.
Why should you install your own irrigation system? Here are a few good reasons:
* It can cost as much as half of what it would cost to hire an irrigation professional.
* The system can be tailored to meet your own standards.
* In the event that your system needs repair, the underground pipes can easily be found without having to call a professional.
Automatic or manual
The first step is to decide whether your irrigation system is going to be manually or automatically operated. If attached to the mains, a manual system is operated with a ball valve that can be opened and closed manually to let water into the irrigation system directly from the mains water supply. Otherwise it can be attached to the tap by means of quick-clip connectors, convenient links between a tap, hose and sprinkler.
An automatically operated system can be programmed to water the garden on specifically chosen days and times. To get the full benefit from an irrigation system, an automatic system is recommended because it saves time and will enable watering while you are on holiday, during off-peak times when water pressure is high and give different areas of the garden specified, pre-programmed amounts of water. The most important equipment in an automatic irrigation system are the solenoid valves and controller.
A controller regulates the irrigation schedule. Usually there is insufficient water pressure to water the whole garden at once, so the system is broken up into zones, each with a separate valve. The basic controller is a 220 volt unit that sends an electric impulse to the solenoid valve. It is programmed to water at specific times on specific days which will vary according to season, plant types and soil types.
A valve can be a ball valve for manual irrigation systems or a solenoid valve for automatic systems. Whereas a ball valve is operated manually to let water through to the system, a solenoid valve is operated by a controller for a pre-programmed period. A valve is needed for each zone in the irrigation system, making irrigation of different areas with different water needs possible. A solenoid valve has a 24V AC current, a low voltage which can be installed by the layman at no risk.
Tips for irrigation success
* Rather than linking your irrigation system to the tap, link it directly to the mains water pipe to avoid a loss of up to 40 percent in water pressure.
* Sprinklers should always be placed along the edge of areas to be irrigated, directing the water flow towards the area needing irrigation. This keeps water off paved areas, such as driveways, thereby conserving water.
* Sprinklers should always be placed so that their sprays overlap by at least 75 percent, so the spray of one sprinkler reaches the other to give uniform water coverage.
Within one zone or station, use only one sprinkler size (radius of spray) and type (pop-ups, shrub sprayers). Different configurations (degree of spray) can be used.
* Try to use the same amount of water per station.
* Select the correct pipe size according to available pressure. If the diameter is too small, pressure at the sprinkler will suffer.
* Pipes should be buried about 300mm underground to avoid damage.
* Differentiation should be made between pipes constantly under pressure from water and those only under pressure once the system is in operation. A stronger pipe for constant water pressure is essential to prevent bursting.
If you would prefer professional help, consult the Landscape Irrigation Association on www.liasa.co.za for a list of irrigation professionals. - Saturday Star