Is your sprinkler system overwatering parts of your yard? One easy solution is to learn how to cap a sprinkler head. In a few minutes, you’ll adjust the flow of water to your entire yard and restore balance to your watering system. Here’s how to cap a sprinkler head in six steps.
Prepping to Cap a Sprinkler Head
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Before you can cap a sprinkler head, you’ll need to find a sprinkler cap compatible with your sprinkler system. Many sprinkler systems will already include caps in the kit, but if you’ve long lost those after moving to a new house or spring cleaning the garage, no problem. You can find a matching cap by brand or size at a local home improvement, hardware store, or online. Note down your sprinkler system make and model; an employee can help you find the right caps if needed.
Another option is to cap the sprinkler head with a threaded PVC cap. If you go this route, you’ll need to know the size of your sprinkler pipes to find a matching PVC cap. Most sprinkler pipes are about 1/2 to 3/4 inches, but check your manual (either a physical copy or online) to verify. If you use the wrong size caps, you could have a sprinkler head leak, so don’t rush through the buying process.
Turn Off the Sprinklers and Water
Before you get started, it’s important to ensure your sprinkler system is off, and the water going to the sprinklers is also off. It wouldn’t be pleasant to pull out the sprinkler head only to have the timer click on and spray water in your face.
Ensure the sprinkler system is shut off, and head to the valve that supplies water to your sprinklers. This valve is usually located on the side of the house. Turn it clockwise to shut the water to the sprinklers off.
Uncover the Sprinkler Head
Using a small shovel, dig carefully around the sprinkler head you want to cap. You’ll need to remove the dirt until you reach the riser or where the sprinkler head and assembly connect to the lateral pipes supplying it with water. That way, you can easily access the entire sprinkler head. This process will involve digging about 1 to 2 inches around the sprinkler head and about 6 inches deep.
Remove the Sprinkler Head
Now that the sprinkler head is uncovered and you have enough room to reach down toward the sprinkler riser, grab the sprinkler head, which includes the sprinkler cap and its assembly, and turn it left or counterclockwise. Below, you’ll now see the exposed riser in the ground.
Take Out the Existing Sprinkler Cap
The existing sprinkler cap has a small opening and screw on top to release and spray out the water, but you’ll want to replace this with a flat cap that stops the water. Remove the existing cap, including the interior assembly, from the sprinkler head and set it aside. You’ll want to store it in a garden shed or garage, where you can easily reaccess it if you decide to uncap this sprinkler head.
Screw on the Cap
Tighten the flat cap that is compatible with your sprinkler system onto the sprinkler head. This provides a temporary option for capping a sprinkler head, which can be helpful when winterizing your sprinkler system or allowing newly planted flowers to acclimate to your garden.
However, if you know it’ll be a long time before you uncap this sprinkler head, you may want to consider capping it with a threaded PVC cap. The process is similar, but instead of capping the sprinkler head and attaching it back to its riser, you’ll simply screw the PVC cap directly onto the sprinkler riser.
Thread the Capped Sprinkler Head Into Place
If you use a threaded PVC cap to cap the sprinkler head permanently, you can skip this final step. If you screwed on a flat cap to the sprinkler head, now screw the entire sprinkler head back onto its riser, being careful not to overtighten.
You can now fill the hole with dirt and turn the water and sprinklers back on.
How to Winterize and Cap Sprinkler Heads
There’s another reason to cap sprinklers—winterization to preserve your sprinkler system during the coldest months. Sprinkler systems in regions that experience freezing temperatures are “blown out” so freezing won’t cause problems.
You cannot directly cap a sprinkler head in areas with cold winters because that prevents water in that end of the irrigation pipe from getting blown out. It lingers and can freeze when temperatures drop, potentially damaging irrigation pipes. It’s usually better to cap permanently or not cap so sprinklers can be blown out effectively. Instead, the capping process works like this:
Find the sprinkler head that you want to permanently cap. Locate the closest upstream sprinkler (the next sprinkler the irrigation water would reach before the head).
Carefully dig up the irrigation pipe, from the final sprinkler you want to cap to the next sprinkler in line, fully exposing the pipe.
Cut the pipe horizontally at the T section as the irrigation pipe passes the upstream sprinkler head. You’ll want to leave 1 or 2 inches to fully cap it, but otherwise cut it as close to the T branch as possible.
Cap the horizontal pipe as you would with a sprinkler head, making sure the pipe stays dirt-free during the process.
Remove the section of irrigation pipe and end the sprinkler entirely. You can disconnect the sprinkler and store it for spare parts.
Use this method to cap a sprinkler line in the middle. You’ll have to repeat the process for two sprinklers on either side instead of one, and make sure both lines have a connection back to the irrigation pump.
DIY vs. Hiring a Pro
Capping a sprinkler is an easy DIY project for any homeowner. If you already have some gardening or work gloves and a small shovel, you’ll just need to buy a sprinkler cap, which typically costs less than $5.
Hiring a pro to inspect a sprinkler costs about $115 on average, but this process involves more than just capping a single sprinkler head. The pros can inspect the entire system for any problems that could be wasting water and costing you money. They can also help you determine which sprinklers to cap for best yard results.
If you don’t intend to use a sprinkler head any more, you can cap it and prevent it from spraying water. That saves water and prevents accidental overwatering or water damage. Capping sprinklers also helps you hide sprinkler heads you no longer want to use. This method is common when you make landscaping changes in the yard like new bushes, fences, rocks, pathways, or dug-out sod.
Yes, the type of sprinkler head is not a concern for capping. The important part is knowing the type and size of the irrigation pipe, so you can get the right capping supplies. You can find and measure the irrigation pipe by digging out around the sprinkler slightly. Most sprinkler systems use standardized PVC pipe.
There’s no limit to how many sprinkler heads you can cap—as long as you pay attention to the effect it has on the remaining heads. Those sprinkler heads will experience more water pressure, which means they may shoot farther. Cap enough heads and the water pressure could rise high enough to damage your irrigation system. However, this is rare in standard home sprinklers unless you have more sensitive drip sprinklers.
Capping a sprinkler may or may not save water. It might save some water from spraying out of a particular sprinkler head, but it could also increase the water pressure and allow more water to spray from the other sprinkler heads. Either way, the change to your system will likely be minimal.
The small screw on the sprinkler head helps adjust the sprinkler and its water spray. You can turn it to the right to increase how far the water sprays out from the sprinkler head or turn it to the left for the water to spray closer to the head. If your sprinkler is spraying too much water in one area, you may want to try adjusting the spray first. If that doesn’t work, go ahead and cap the sprinkler head.
Tyler Lacoma has spent more than 10 years testing home technology and the latest tools to help keep readers current for their next project. His published work can be found on Family Handyman, U.S. News & World Report, and Digital Trends.
Tyler Lacoma has spent more than 10 years testing home technology and the latest tools to help keep readers current for their next project. His published work can be found on Family Handyman, U.S. News & World Report, and Digital Trends.
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