Determine any potential obstacles — such as trees — that may block sprinkler patterns, as well as curves in the landscape design that might require special attention. Carefully measure property boundaries and record the numbers on a diagram of the layout. Use graph paper for the plan to allow the irrigation system to be drawn to scale and accurately plotted. Draw in the street, driveway, sidewalk, and house, as well as landscape elements such as flowerbeds, trees, etc.
Once the property layout is on paper, it's time to evaluate the various system components and sprinkler heads available and determine the best way to pull it all together. To start this process, learn the basic elements of an irrigation system and their respective features: Polyethylene pipe (Image 1) is the recommended choice for most irrigation systems. Flexible, lightweight and highly durable, it's often referred to simply as "poly" (pronounced "polly"). While PVC pipe (Image 2) is probably more familiar to most people than poly pipe, it's generally not the best choice for irrigation systems. Its rigid composition and lack of flexibility can make it difficult to work with, especially in applications where curves and corners require a pliable material like poly. (The importance of flexibility will be evident in the upcoming installation.)
Next, learn about the basic fittings used for a typical system assembly. Like the flexible tubing, these components are molded from polyethylene. Featured pieces include: The straight coupler (Image 1). This fitting is used to connect two pieces of pipe that meet at a certain point or to extend a length of pipe that's too short to reach the necessary area. The poly plug (Image 2), shaped, appropriately, like a stop sign, is used at the end of a pipe length to stop water at a designated point. The elbow coupler (Image 3) is sometimes referred to simply as a "90", since it creates a 90-degree angle in a system of pipes. In short, it's used to change the direction of the water, allowing the system to turn a corner. The T-coupler (Image 4) fitting is designed to join together three pipes at one intersection, either coming off a main line or leading to a valve. To control the release of the water into the pipes, electronic valves (Image 5) are integrated into the system.
To illustrate how the valves will work with the pipes, create a T-formation mock-up of a section (Image 1), and connect with a T-coupler fitting. (The top pipe of the "T" sample represents the main line.) Coils of wire on top of each valve (Image 2) — known as solenoids — will connect them to the individual zones. Finally, a programmed clock will be wired to all valves in the system, activating them at the appropriate, pre-set times. Once signaled by the clock, each valve will open, letting water into its corresponding zone. In turn, the water will prompt the sprinkler heads to pop up and begin spraying their designated areas.