Skip to main content

Install Shutoff and Rebuild Riser — Cut the Water Line

Beginner3 hours

Part of project

How to Install a Water Hammer Arrestor to Stop Banging Pipes · Step 3 of 5

Helpful?

In this video

Install a shutoff valve and begin rebuilding the riser. The plumber uses the cutter's deburring tool to remove any burrs or rough edges from the inside of the copper pipe and ensure a smooth, even surface for proper fitting connections and prevent leaks or flow restrictions.

Goal: Install the shutoff valve at the beginning of the pump loop.

  • Dry fit all connections before soldering or crimping any connections.
  • Use Teflon tape or pipe sealant before soldering the fittings on the shut off valve.

Used in this video

  • Pipe Reamer · optionalReaming or deburring copper pipes
1.2M views7.5K10 minutes
This Old House

2.2M subscribers

View Channel

FAQs

How do I accurately identify the source of water hammer before installing the arrestor?

Listen carefully for the banging sound when a specific faucet, toilet, or appliance (like a washing machine) shuts off abruptly. You can also try gently touching the water lines near suspect fixtures to feel for vibrations when the noise occurs. Installing the arrestor as close as possible to the identified source will yield the best results.

What crucial safety steps must I take before cutting into the water line?

Always turn off the main water supply to your entire home first. Then, open the lowest faucet in your house (e.g., in a basement or outdoor spigot) and the highest faucet to completely drain the water from the pipes. This prevents unexpected water leaks and potential injury while you work.

Do I need special tools to cut copper pipes, and how do I ensure a leak-free connection?

Yes, a copper pipe tubing cutter (e.g., AUTOCUT 1/2 in.) is essential for a clean, straight cut. After cutting, use a reamer and deburring tool (like the Husky 1-5/8 in.) to smooth the pipe's interior and exterior edges. This deburring step is critical for proper sealing and preventing leaks, especially with push-to-connect fittings.

What's the best way to prevent leaks when installing the tee fitting and water hammer arrestor?

Ensure the pipe ends are perfectly clean, smooth, and free of scratches or burrs. Use a depth gauge (like the Tectite Depth Gauge) to mark the correct insertion depth on the pipe for push-to-connect fittings, ensuring it's fully seated. For the arrestor's threaded connection, apply several wraps of PTFE plumber's tape (Harvey 1/2 in. x 260 in.) clockwise to the male threads before tightening.