Pinhole Leaks in Copper Pipes: Causes, Signs and When to Repipe

Copper pipe has a reputation for lasting a lifetime, and often it does. But copper can develop pinhole leaks: tiny holes that start as a slow drip or fine spray, usually hidden inside a wall or ceiling. By the time you notice, there may already be water damage. Here's what causes them and what to do.

What Causes Pinhole Leaks

Pinhole leaks come from corrosion that starts on the inside of the pipe and eats through a small spot. Several things can contribute:

• Water chemistry. Water that's slightly aggressive toward copper, because of its pH, minerals or treatment chemicals, can wear it away over time.
• High water velocity, especially around elbows and fittings, where turbulence erodes the pipe wall.
• Sediment and debris that scour the inside of the pipe.
• Age. Copper in homes from the 1960s through the 1980s is now 40 to 60 years old.
• Installation issues, like excess flux left inside joints, or pipe that's undersized for the flow.

Signs of a Pinhole Leak

• Water stains or bubbling paint on ceilings or walls
• Damp drywall, a musty smell or mold
• A hissing sound in a wall when no water is running
• A water bill that jumps without explanation
• Green or blue spots on exposed copper pipe
• Your water meter moving with everything turned off. See the meter test.

If you can't see where the water is coming from, a leak detection company may need to locate it first. Then the pipe can be repaired.

Spot Repair or Repipe?

One pinhole leak in otherwise healthy pipe can be repaired by replacing the damaged section.

A second or third pinhole leak is a different story. Pinholes usually mean the conditions that caused the first one are working on the rest of the system. Each new leak risks more water damage inside walls and ceilings. At that point, a repipe with PEX is usually the better investment. PEX resists the kind of corrosion that causes pinholes and holds up well in hard water. See signs you need a repipe.

Insurance

Water damage from a sudden pinhole leak may be covered by homeowner's insurance, but repeated leaks and long-term damage often aren't, and some insurers ask about a home's leak history. Document any leak and its repair, and check your policy.

Pinhole Leak Help

Believe Plumbing repairs copper pipe leaks and repipes homes across Tampa Bay. We'll tell you honestly whether a spot repair will hold or a repipe makes more sense. See our pipe repair and repiping services or contact us for a free estimate.