Fixing a Leaking Black Poly Pipe

Black poly pipe with leak being fixed below ground

The Spruce / Kevin Norris

Project Overview
  • Working Time: 3 - 4 hrs
  • Total Time: 3 - 4 hrs
  • Skill Level: Intermediate
  • Estimated Cost: $20 to $30

Black polyethylene, or PE, pipe comes in very long rolls and is used in many areas for the water main between the meter and the house and for sprinkler systems. Just like any other type of pipe, poly pipe does not last forever and can develop leaks with time and with the help of tree roots. As roots grow they push against the pipe and eventually break it. Poly pipe also can be damaged by rocks in the soil that may shift and apply pressure to the pipe.

Get Ready to Dig

Repairs in this type of pipe can be difficult if it is installed deep in the ground and the hole is not big enough to allow for plenty of pipe movement. Locating the source of the leak can also be difficult. Sometimes you will be able to locate the problem by digging up the wet area in your yard. However, you may not always get so lucky and the wet spot will be a long way from the actual leak if the water follows a gopher hole or other type of cavity. Either way, expect to do a fair amount of digging.

Call Before You Dig

Be sure to call 8-1-1, the national call center of the "Call Before You Dig" program. The center will notify all utility companies with service lines on your property. The companies will send someone out to mark their lines, which may take up to three days but usually is free-of-charge. You must have your lines marked before digging in your yard, to prevent accidental contact with, or damage to, utility lines, including electrical, gas, water, and cable lines.

What You'll Need

Equipment / Tools

  • Shovel
  • Trenching-style shovel
  • Wood shears (optional)
  • Pipe cutter
  • Handheld torch (optional)
  • Screwdriver
  • Pinch clamp tool (or similar)


  • Brass barb couplings
  • Hose clamps
  • Hot tap water (optional)
  • Liquid soap (optional)


Materials and tools to fix a leaking black poly pipe

The Spruce / Kevin Norris

How to Fix a Black Poly Pipe

The standard repair for a black PE pipe is to install one or more brass barbed couplings secured with hose clamps. You will need to use specific clamps (ones used to secure pipe to fittings) and a tool that squeezes the clamp around the pipe securely. It is good practice to double up on the clamp on each joint for extra strength at the connection.

It's best to use couplings with a nut portion in the center to identify that the fittings are brass, which is required in many areas. If the damaged portion of pipe is large, you will need two fittings and a new section of PE pipe to make a spliced connection. Be sure to follow all local code requirements for the repair.


If the pipe you are repairing carries potable water, you may need to use different connections and fittings. Check your local codes to ensure you're using the proper tools and materials.

  1. Shut the Water Off

    You don’t want to be bailing water while you are trying to dig. You can always turn the water on if you think you are getting close to the leak. Or, turn the water on once the pipe is exposed to see exactly where the leak is located.

    Water pipe turned off by turning shutoff valve lever

    The Spruce / Kevin Norris

  2. Dig Carefully

    Unless you know how deep the pipe is located, you should dig carefully so that you don’t end up hitting the pipe. If you know about how deep it is, you can dig the first bit quickly until you get closer. Otherwise, dig slowly. As you get close to the right depth, switch to a smaller trenching-style shovel for more control. Make sure to expose all the way around and under the pipe to make it easy for you to work. Also, cut back any roots and remove any rocks that may damage the water line now or in the future.

    Shovel digging carefully around black poly pipe underground

    The Spruce / Kevin Norris

  3. Plan the Cut

    First double-check the location of the leak. It’s important to pinpoint where the leak actually is so that you can decide what fittings you’ll use for the repair. If the leak is at a tee, you may be able to loosen the clamps and remove the barbed tee from the pipe so that only one pipe has to be cut. Since you may have only a little room to work with, you want to avoid shortening the pipe on more than one side of a fitting, if possible. Decide how best to cut the pipe to make the repair based on where it is located. Then use a pipe cutter to cut the pipe.

    Exposed black poly pipe being cute with blue pipe cutter to make repair

    The Spruce / Kevin Norris

  4. Install the Fittings

    Put the pipe clamps onto the pipe before inserting the each barbed fitting into the pipe. Insert one end of the fitting into the pipe, pushing it in as far as it will go. It can help to heat up the pipe by dipping it in a bowl of very hot tap water (not boiling water) or use a little liquid soap to lubricate the barbs if you have trouble pushing the fitting in.


    If you're still having trouble pushing the fitting in, you can try using a small handheld torch (if you have one) to heat the pipe. Heat it quickly by waving the flame over the first four inches of pipe, then try pushing the fitting in—it should be much easier now.

    Lift both ends of the pipe, line up the other end of the fitting to the opposite pipe and push the fitting into the pipe as you push the pipe down.

    Black poly pipe inserted with barbed fitting and pipe clamps

    The Spruce / Kevin Norris

  5. Tighten the Clamps

    Slide the hose clamps up so they are positioned over the barbs. Tighten each of the hose clamps with a screwdriver, using the pinch clamp tool if necessary. Make sure the clamps are secure and don’t move around.

    Black poly pipe with hose clamps tightened with screwdriver

    The Spruce / Kevin Norris

  6. Check for Leaks

    Turn the water on to check for leaks before backfilling over the pipe. Sometimes the clamps will need a little extra tightening, so give them plenty of time to be sure they aren’t going to leak before you cover them up. Once you are certain nothing is leaking, backfill the dirt, being careful to pack the dirt down around the pipe as you go to prevent disturbing the fittings.

    Black poly pipe checked for leaks with clamps secured

    The Spruce / Kevin Norris