How to Install a Sprinkler System With a PVC Pipe

Insert a marker into your yard for every sprinkler location. Mark the grass with a spray or string in a single line according to your plans to indicate where you'll need to trench. Dig trenches in the ground at least 8 to 12 inches deep by hand or with a trenching machine. Lay out the proper PVC pipes and connected fittings along the trenches.

Locate the main water line valve, which is usually beside the meter, and twist it to shut it off. Make two incisions in the main line using a PVC pipe cutter, cutting out a section just big enough for a slip-type compression T. Do not cut the section too big. Unscrew both sides of the T and slide one onto each open end of the cut main line along with the accompanying rubber washers. Wrap Teflon tape around the threaded ends of the compression T. Slide the T between the two main line sections and screw the two T connectors onto the T tightly. Always use a wrench to finish tightening each fitting, but do not exceed more than one and a half additional turns.

Wrap the threads of three PVC fittings in Teflon tape and screw one into the open end of the T and the other two into both ends of a shut-off valve. Cut a small 3-inch-long section of PVC pipe. Sand the ends of the PVC pipe to smooth rough edges and prepare it for a good seal. Wipe the ends with a PVC primer and then gently wipe the inside of the connected fittings and pipe ends with PVC glue. Slide the pipe section into the T fitting and twist it a quarter turn. Hold the pipe in place for 10 to 15 seconds per each fitting to allow the glue to set. Slide the shut-off valve and its fitting onto the open end of the PVC section.

Turn the new shut-off valve until it's in the off position, and turn the main water supply back on. (Install a back-flow prevention valve at this time just after the shut-off valve, if your plan calls for it.)

Sand, prime and glue the PVC pipe, going from the shut-off valve to the manifold valve location, into the open end of the shut-off valve. Lower the irrigation controller valve wire into the same trench as the PVC pipe that leads to the manifold valve location, and tape the wire to the pipe to secure it.

Cut small sections of PVC pipe and lay out the fittings necessary to link the water valves together. This section is known as the valve manifold and should already be mapped out in your plans. Allow at least 3 inches of PVC pipe between each fitting to give yourself room to work, should you need to take the valves apart later for repair or cleaning. Wrap the threads of each fitting in Teflon tape and screw them into each water valve opening. The water supply should enter the water valve at its inlet that may or may not be marked "Flow." Sand, prime and glue each PVC fitting and pipe section. Slip the PVC sections into each fitting, giving each a quarter turn to seal it well. Turn each added fitting, so that the entire manifold sits flush to the ground.

Pull out the two wires from each water valve. Strip the tip of one wire from each valve -- it doesn't matter which -- and twist them together, linking each valve. Expose three wires from the controller valve wire that was laid in the trench including the white wire, and fold back the rest of the wires so that they're out of the way. Take note of the other two wire colors. Use a wire stripper to strip a half inch of insulation from the three exposed controller wires.

Twist the free wire of each valve to one of the free wires from the controller wire, except the white one, which is the common wire. Twist a wire connection easy cap onto the end of each wire union. Twist the already joined valve wires to the white controller wire and twist a wire connection easy cap over the tips. Slide each of the three connections into waterproof wire nuts or grease caps to protect them from the elements.

Sand, prime and glue the laid-out pipes from each zone into its designated water valve. Sand, prime and glue all laid out pipes and fittings together. Install a threaded fitting between the PVC lines at each sprinkler location. Screw a swing-pipe assembly into the fitting until it's tight. Screw the sprinkler housing onto the free end of the swing-pipe assembly by hand, until it's tight. Repeat this step until the entire sprinkler system is put together.

Unscrew the tops off all sprinklers and unscrew each water valve bleed screw, located on top of the water valve, about a quarter turn. You'll hear the water rush through the system. Flush the system until the water runs clear from each open sprinkler. Twist the bleed screw clockwise to close it and screw the sprinkler tops back on.

Fill the trenches and bury the PVC pipes with the unearthed dirt. Bury the sprinkler housings so that they are vertical for optimum performance. The top of the sprinkler should be slightly above and level with the ground.

Place the water valve box over the valve manifold and fill in the trench with unearthed dirt around the box.

Insert the same colored controller wires that are connected to the water valves into the corresponding zone terminals of the irrigation controller. Insert the white wire into the "Common" terminal. Supply power to the controller and program it.