Bio Green Outdoor Services, LLC Lawn Care & Sprinkler Learning Center (703) 450-0034

Sprinkler systems are a valuable investment in your lawn and your property as a whole. They’re also permanently buried underground, so it’s important that your sprinkler system is installed right the first time. Since sprinkler systems are a plumbing fixture, the underground plumbing that powers them is the most critical part of the entire system.

The first step in installing a sprinkler system is checking that your home’s plumbing supply provides sufficient pressure and volume to power a sprinkler system. If your plumbing passes the test, the next step is designing a sprinkler system to suit your lawn and landscape with proper zoning. Once all the supplies are acquired, trenches are dug into your lawn to bury the plumbing for the sprinkler system and the sprinkler heads themselves. Another critical step is the installation of a backflow preventer, which protects your potable water supply. Finally, your system’s controller is wired up and programmed to run your sprinkler system.

Best Practices for Sprinkler System Plumbing

  • Uniform application is a main goal of an irrigation system so that your lawn is green and healthy throughout. Uniform application starts with uniform pressure, so it’s best to use plumbing for your system that is appropriately sized. For most sprinkler systems, 1” pipe is ideal for properly distributing pressure and most sprinkler heads are designed specifically for this size pipe. Pipe that is too small (like ¾”) or too large will not distribute pressure properly and is prone to malfunction. ¾” pipe is usually cheaper, but is not better because it carries the risk of water hammer and cavitations through the fittings, which are two major causes of piping failures.
  • Some contractors use polyethylene pipe (better known as “polypipe”) for irrigation system plumbing. Polypipe is a thin, flexible pipe that is easy and inexpensive to install, but is prone to numerous problems like kinking and leaky connections when used improperly or installed incorrectly. Polyethylene pipe is widely deployed in northern areas of the United States due to its flexibility for freeze resistance. For best results in the Northern Virginia area, ensure that your irrigation contractor uses solid plumbing materials like PVC and installs such piping below the freeze line.
  • Irrigation systems typically connect to your home’s main plumbing system. This important hook-up should be done by someone who is properly licensed and knows what they’re doing, such as a master plumber. In addition, it’s important that the hook-up uses quality materials, like copper. Copper is used for plumbing hook-ups in most homes anyway, and offers durability, reliability, and safety. The pressure reducer from your hook-up to your sprinkler system should be copper as well.
  • Another important component of any sprinkler system plumbing is a backflow preventer. Backflow preventers ensure that the non-potable water that flows through your sprinkler system does not flow back into your home’s water supply. According to the plumbing codes in some areas, backflow preventers are required. Check that a backflow preventer is installed on your system for safety.
  • Your irrigation contractor should bury your sprinkler system’s plumbing deep enough. Some contractors will cut corners and bury pipe only 2–3” deep, and this isn’t safe or sustainable. This becomes a problem with any major erosion or common lawn care operations, like core aeration. A good contractor will bury your system’s plumbing at least 6–8” deep.

Bio Green is happy to help with any irrigation plumbing questions you may have. Call our office in Sterling, Virginia at (703) 450-0034 or visit our website at

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