Cold Weather Damage to Lawn Sprinkler Systems

Pipes

• Sprinkler pipes are usually made out of PVC plastic, which is a very durable material that resists corrosion. However, the plastic is not as durable as metal pipes and can crack easily when water freezes inside. Removing as much water as possible from inside your sprinkler pipes before the first hard freeze of the season is critical and can be accomplished by blowing out your system with compressed air or draining the pipes through a drain valve.

Vacuum Breakers

• Pressure vacuum breakers sit above the sprinkler manifold outside the house. These are important safety devices that prevent water from flowing from the sprinkler pipes back into the main line. Many areas require vacuum breakers by code. These devices are made out of brass, but because they sit above the ground and are exposed to the cold air, they are also subject to breakage during cold weather. Remove all the water from inside the vacuum breaker every year by removing the small drain cap on the bottom of the breaker.

Manifolds

• Sprinkler manifolds control the flow of water from the main line to each zone on the system. These valves are connected by a large pipe. When water freezes inside this pipe, the valves can break. You must remove all the water from the manifold by releasing the drain cap on the end of the manifold. Replacing a damaged manifold is one of the most labor-intensive projects on a sprinkler system.

Sprinklers

• Sprinkler heads also can be damaged by cold weather. If water is left inside the sprinkler pipes, it can expand up to the sprinkler head. The pressure from the frozen water can snap off sprinkler heads completely, leading to a gusher of a problem in the spring. You can prevent damage to the sprinkler heads by removing all the water from the sprinkler pipes. Sprinkler heads that are damaged can be replaced easily by unscrewing them from the riser below and replacing them with a new unit.