Capping sprinkler heads is a wise idea when you need to winterize your sprinkler system, or if you need to shut it down for a period of time. You may also want to cap a head when it is no longer being used because you’ve redesigned the system or made changes in your landscape.

How Does a Sprinkler Cap Work?

Before you install a cap you need to understand how it works. If you don’t have to worry about frozen pipes, then water can still run through the lines connected to the sprinkler head you’re capping off. The cap just covers the sprinkler head, ideally with a water-tight seal. Water can’t come out of the head, but the other working sprinkler heads in the system relieve the pressure.

The quality of the seal on the cap is therefore the most important thing. It’ll be stressed by the rest of the system, so it needs to hold up. We recommend that you only attempt to cap your sprinkler head with a cap specifically designed for the system.

Tools and Supplies

In order to cap your sprinkler heads you will need the following:

  • Trowel
  • Shovel
  • Pliers
  • A cap made for your sprinkler head
  • Teflon tape or plumber’s tape

How to Cap Off a Sprinkler Head

  • Step One: Start by turning off the sprinkler system at the main valve. You don’t want it to start running while you’re using it.
  • Step Two: Dig out the sprinkler head. Using the trowel or a shovel, carefully remove a small amount of dirt around the sprinkler head. Make sure there is enough room to access the sprinkler head on all sides. This keeps dirt from getting into the sprinkler cap and make work easier.
  • Step Three: Remove the cap. This is a little confusing, but the cap that’s on the sprinkler right now needs to be removed before you can install the flat cap you purchased onto it. You should be able to twist the cap counterclockwise in order to loosen it. If it can’t be turned, then try to use the pliers to get it off. If it takes a lot of effort, you may want to check in with your sprinkler’s owner’s manual to see how you can get the head of the sprinkler off.
  • Step Four: The same thread that held the sprinkler head in place is now ready for you to screw the cap onto. You can optionally wrap some of the plumbing tape around the threads to ensure it will create a watertight seal.
  • Step Five: Check the seal to ensure it is good. Turn the sprinkler system back on and run it. Watch the cap to ensure that there are no leaks. If there is, you may need to adjust the cap.
  • Step Six: Once you’re sure the seal is good, you can put the dirt back around the sprinkler cap.