How to Install an In-Ground Lawn Irrigation System

Irrigation is the difference between a landscape that survives the summer and one that thrives. By moving away from dragging hoses across your grass, you save countless hours and ensure your lawn receives deep, consistent hydration exactly when it needs it. A well-installed system hides beneath the surface, operating on a schedule that keeps your soil moisture constant without wasting a drop. Success in this project lies in the planning. Before you break ground, you must calculate your water pressure and flow rate to ensure your zones have enough power to pop up the sprinklers. Done well, your system will be nearly invisible, with heads that retract flush to the soil, allowing you to mow right over them without a second thought.

1. Group by Water Needs. Draw your yard to scale on graph paper, grouping plants with similar water needs together. Place sprinkler heads so that the spray of one head reaches the base of the next to ensure 100% head-to-head coverage.
2. Mark Before You Dig. Use landscaping flags or marking paint to outline where the pipes will run and where each sprinkler head will sit. Cross-check these lines against any known utility locations to avoid cutting lines.
3. Cut Deep Trenches. Dig trenches 8 to 12 inches deep along your marked lines using a rented trenching machine or a sharp spade. Keep the sod in one piece on a tarp so you can replace it easily once the pipe is laid.
4. Seal Every Joint Right. Lay out your PVC pipe lengths, cleaning each joint with primer before applying PVC cement. Press the pipe firmly into the fitting and hold for 30 seconds to create a permanent, watertight seal.
5. Mount Flush to Grade. Attach the heads to the PVC pipe using flexible swing pipe risers. This allows you to adjust the height of the sprinkler head so it sits perfectly flush with the ground level.
6. Wire and Label Zones. Connect the electric irrigation valves to the multi-strand wire running back to your irrigation timer. Use waterproof wire connectors to ensure the electrical joints do not corrode in the damp soil.
7. Test, Then Backfill. Turn on the water supply slowly to flush out any dirt from the pipes before attaching the nozzles. Once you verify there are no leaks and the coverage is even, backfill the trenches and tamp down the soil.