Leaks in a Plastic Pipe Sprinkler System

Freezing Damage

• All plastic pipes within a sprinkler system are susceptible to damage from freezing. Freezing the pipe itself is not a problem, as PVC can withstand extreme temperatures. However, when water freezes inside the pipes, it expands. This expansion causes pressure to build against the walls of the pipe. With nowhere else to go, the pressure can break the PVC pipe or cause cracks. When the temperatures rise again, cracks can cause pipes to burst at any time. It's critical to remove as much water as possible from plastic sprinkler pipes before a deep freeze.

Manifold Leaks

• A sprinkler manifold is made out of a series of PVC pipes that connect to valves. These valves control the flow of water within your irrigation system. The points where the valves connect to the manifold can leak if not properly secure. This connection point requires the use of Teflon tape around the pipe threads before tightening the valves. This is the most common place for leaks to go unnoticed, so check your manifold at least once per season to see if a leak has developed.

Riser Leaks

• All sprinklers sit on a device called a riser. This is also a plastic or PVC pipe that has pipe threads on either end. One end screws into the supply line underground, while the other end attaches to the bottom of the sprinkler. But sprinkler risers use thinner plastic than PVC supply lines. These thin walls mean there is a greater risk of damage from frozen water or accidental puncture. When working with risers, be careful not to bend them, as that can also lead to leaks.

Repair

• Fortunately, PVC pipe is simple to repair. Most home-improvement stores carry a large selection of PVC couplers and clamps. Couplers have an extendable body that glues to either end of a broken pipe. These are the most secure means of fixing a burst pipe or a leak caused by a crack. Clamps rely on a rubber gasket that presses against the area of a leak to stop the flow of water. Clamps are secured with pressure from two or more nuts and bolts.