Moving a sprinkler line is a straightforward DIY project that takes most homeowners a few hours. Whether you’re rerouting around a new patio, garden bed, or driveway extension, the process comes down to digging up the existing pipe, cutting it at the right points, and reconnecting it along a new path. The key is working methodically so you don’t damage other lines or lose water pressure in the process.
What You’ll Need
Gather everything before you start digging. You’ll need a flat shovel and a narrow trenching shovel (or a manual trencher if the run is long), pipe cutters, PVC primer and solvent cement (for PVC systems) or barb fittings and hose clamps (for poly pipe), a measuring tape, and the appropriate fittings for your pipe size. Couplings, elbows, and tees are the most common fittings for rerouting work. Pipe wrenches help when removing threaded risers from existing fittings.
Pick up spray paint or landscape flags to mark your new route before you dig. A few extra repair couplings are worth having on hand in case you accidentally nick an adjacent line.
Locate and Mark Your Lines
Turn on each sprinkler zone one at a time and watch which heads activate. This tells you which line you’re working with and where it runs. Most residential sprinkler lines follow relatively straight paths between heads, so you can trace the approximate route by connecting the dots between active heads in a zone.
Before digging, call 811 (the national “Call Before You Dig” line) to have utility companies mark gas, electric, and water mains. This is free and usually completed within a few business days. Once utilities are marked, use spray paint to outline your new trench path and the section of existing pipe you plan to remove or disconnect.
Dig Up the Existing Line
Shut off the water supply to your irrigation system. Open a valve or turn on the zone briefly to bleed off any remaining pressure, then shut it back off. Start digging carefully along the marked path of your existing line. Residential irrigation pipe is typically buried with at least 6 inches of soil cover above the top of the pipe, though you may find it shallower in areas where tree roots or rock forced the original installer to go less deep (code allows as little as 2 inches of cover when obstacles make standard depth impractical).
Expose enough pipe on either side of where you plan to cut so you have room to work with fittings. About 6 to 8 inches of exposed pipe on each side of your cut point gives you comfortable clearance.
Cut and Cap the Old Run
Use a pipe cutter or a hacksaw to make clean, square cuts at the points where the new route will branch off from the existing line. Rough or angled cuts make for weak joints. If you’re removing a section entirely, cut at both ends and pull out the old pipe and any attached heads.
If you’re capping off one end permanently (say, because you’re shortening a line), glue on an end cap. If you’re rerouting, this is where you’ll install a tee or elbow fitting to redirect flow toward the new path.
Trench and Lay the New Route
Dig your new trench to at least 8 inches deep. This gives you 6 inches of soil cover above a standard ¾-inch or 1-inch pipe, meeting code requirements. Keep the trench bottom relatively flat and free of rocks or debris that could stress the pipe over time.
Dry-fit the entire new run before gluing anything. Lay out the pipe, fittings, and risers for each sprinkler head along the trench and confirm that everything lines up. Check that your heads will sit at the correct height, flush with the finished grade of your lawn. This test fit saves you from discovering a measurement error after the cement has set.
Connecting PVC Pipe
PVC is the most common material in residential irrigation systems. For each joint, apply primer to both the outside of the pipe and the inside of the fitting, then immediately apply solvent cement to both surfaces and push the pipe into the fitting with a quarter turn. Hold the joint for about 10 seconds to prevent it from pushing back out.
For pipe sizes typical in residential irrigation (½ inch to 1¼ inch), the joint needs at least 15 minutes of cure time at temperatures between 60°F and 100°F before you can pressurize the line. If you’re working in cooler weather, between 40°F and 60°F, wait at least 20 minutes. Below 40°F, give it a minimum of 30 minutes. In humid or damp conditions, add 50% more time to any of those numbers. Residential irrigation systems run well under 180 psi, so these shorter cure times apply to most home setups.
Connecting Poly Pipe
Flexible polyethylene (poly) pipe is common in colder climates because it handles freeze-thaw cycles better. Connections use barbed insert fittings: push the barbed end into the pipe, then secure it with a stainless steel hose clamp tightened snugly. Poly systems generally go together faster because there’s no gluing or curing involved.
Flush Before Closing Up
Before you install the sprinkler heads on the new run, flush the system to clear out dirt, small rocks, and PVC shavings that fell into the pipe during your work. Leave the risers open (no heads attached) and turn on the water for 20 to 30 seconds. You’ll see dirty water blast out at first, then run clear. If you have flushing caps, you can screw those onto the risers and run the zone instead. Either way, don’t skip this step. Debris left in the line will clog your sprinkler nozzles almost immediately.
Once the water runs clean, turn the system off and install your sprinkler heads onto the risers.
Test and Adjust
Turn the zone back on and watch every head in the circuit. You’re checking for three things: leaks at your new joints, correct spray patterns, and adequate pressure at each head.
If you extended the line significantly (added 20 feet or more of pipe, or added extra heads), you may notice reduced pressure at the heads farthest from the valve. Every foot of pipe and every fitting creates friction that reduces pressure. A 90-degree elbow, for example, causes roughly the same pressure drop as several additional feet of straight pipe. If pressure is noticeably low, you have a few options: use heads with lower flow rates, reduce the number of heads on that zone, or switch to a larger pipe diameter for the new section.
Small leaks at joints will usually show as wet spots or bubbling soil within a few minutes of running the zone. If you find one at a PVC joint, you’ll need to cut it out and redo it. There’s no reliable way to patch a bad solvent weld.
Backfill the Trench
Once everything checks out, backfill the trench in layers. Start with a few inches of fine soil (no rocks or clumps) directly around the pipe, then fill the rest with the excavated dirt. Tamp it down lightly as you go to prevent settling later. Overfill the trench slightly, about an inch above grade, because the soil will compact over the next few weeks of watering.
If you had to cut through sod, lay the sod pieces back on top and water them well for a week or two. The seams will grow back together quickly during the growing season. For bare dirt areas, spread grass seed and cover lightly with straw or topsoil to speed recovery.