The expansion or modification of a home irrigation system often seems like a specialized task, but adding a new sprinkler head to an existing line is a manageable do-it-yourself project. Homeowners seeking to improve lawn coverage or address dry spots can accomplish this system upgrade with basic tools and careful planning. This guide details the process of integrating a new head into a currently functioning zone. Successfully completing this task requires understanding the system’s hydraulic limitations and executing a precise connection to the existing piping.
Gathering Supplies and System Planning
Before breaking ground, assess the existing system’s hydraulic capacity to prevent performance degradation. Every irrigation zone operates with a specific flow rate (GPM) and water pressure (PSI). Adding a new sprinkler head draws flow away from existing heads, so the zone’s total GPM requirement must not exceed the supply capacity. This planning ensures the new head does not compromise the spray distance or uniformity of the established coverage area.
The location for the new head must be clearly marked, aligning with recommended spacing (typically 15 to 30 feet apart). The existing lateral line, usually PVC or polyethylene pipe, must be accurately located to determine the connection point. For safety, the water supply to the specific zone must be completely shut off at the control valve before excavation begins.
Gathering materials requires connection hardware, such as a saddle tee fitting for polyethylene lines or a standard solvent-weld T-fitting for PVC pipes. A riser pipe, cut to position the head flush with the finished grade, and the new sprinkler head are also needed. Thread seal tape or pipe dope ensures watertight threaded connections. Tools include a shovel, pipe cutter, safety glasses, and PVC primer and cement.
Connecting the New Sprinkler Head
The physical installation begins with careful excavation to expose the existing lateral pipe at the planned connection point. Dig a trench approximately 18 to 24 inches long and 10 to 12 inches wide to provide adequate working room. The pipe is typically buried 8 to 12 inches deep. Take care not to damage the pipe during digging. Once exposed, clean the pipe surface of dirt and debris to prepare it for the fitting installation.
Installing a PVC T-Fitting
If using a standard solvent-weld T-fitting on rigid PVC, remove a precise section of the pipe using a specialized pipe cutter. The cut must be clean and straight, matching the exact width of the T-fitting. Treat the ends of the cut pipe and the inside of the fitting thoroughly with PVC primer, which softens the plastic surface for a chemical bond. Apply PVC cement quickly and evenly to both surfaces before firmly pushing the fitting into place and holding it for about thirty seconds to initiate the weld.
Installing a Saddle Tee
Alternatively, for flexible polyethylene pipe or to avoid cutting a PVC line, use a saddle tee fitting that clamps directly around the existing pipe. This fitting often includes a sharp internal mechanism designed to pierce the pipe wall after the clamp is secured. Correct tightening ensures a secure, leak-free seal without requiring chemical solvents. Follow the manufacturer’s instructions for curing or securing the connection precisely to achieve maximum joint strength before water pressure is reintroduced.
Once the main fitting is secure, connect the riser pipe vertically, extending upward toward the soil surface. This riser, often Schedule 40 PVC, must be cut to position the sprinkler head just below the grade level to protect it from lawn equipment. Wrap the base of the sprinkler head with two to three layers of thread seal tape, applied clockwise, before screwing it into the top of the riser pipe connection.
Before the final connection is tightened, flush the line to remove any debris introduced during cutting or cementing. Briefly turn on the zone control valve with the riser pipe open and the sprinkler head temporarily detached. Allowing water to flow for a few seconds expels loose plastic shavings or dirt that could clog the nozzle. After flushing, shut off the water, and fully attach and tighten the sprinkler head into place.
Testing the New Zone and Coverage
The final stage involves systematically reintroducing water pressure and observing the new connection point. Turn the main water supply on slowly to allow pressure to build gradually, minimizing stress on the newly installed fittings. Immediately inspect the T-fitting or saddle tee connection to confirm the absence of any leaks or weeping, which indicates a failed seal. If a leak is present, immediately shut off the water and re-evaluate or repair the connection.
With the water running, observe the new sprinkler head for proper function, ensuring the pop-up mechanism extends fully and the water spray is uniform. Calibrate the head’s adjustment screws to set the desired arc of coverage (partial circle to 360 degrees). Adjusting the distance control fine-tunes the spray pattern so it reaches the intended area without excessive overspray. After verifying the absence of leaks and confirming correct spray patterns, carefully backfill the trench with excavated soil, gently compacting it around the new riser pipe.