Pinhole Leak Repair
Pinhole leaks are tiny corrosion pits in copper pipe that spray a fine mist — often inside walls where the damage hides for months. A plumber cuts out the pitted section and installs new pipe, and checks water chemistry since aggressive water causes repeat pinholes. FlowFast connects you with an independent local plumber for the repair.
- Connected with an independent local pro — never a call center queue.
- Part of our Leak Detection & Repair services — explained up front.
Parent service
Leak Detection & RepairHigh water bill or mystery damp spot? How pros find hidden leaks with acoustic and thermal tools, and how to get connected with an independent local plumber.
View all Leak Repair servicesPinhole leaks are copper pipe's quiet failure mode. From the inside out, corrosive water chemistry eats microscopic pits through the pipe wall until one breaks through — sometimes as a weep, sometimes as a fine pressurized spray. Because the hole is tiny, the leak can mist inside a wall cavity for months before a stain appears, soaking insulation and framing the whole time. Homes with multiple pinholes usually share a cause: aggressive water, high velocity from oversized pumps or pressure, or flux residue left inside the pipe from installation.
Repairing one pinhole is simple — cut out the pitted section and splice in new copper. The harder question is whether more are coming, which is why a good plumber inspects the surrounding pipe and asks about water chemistry. If pinholes keep appearing across the system, the honest long-term answer may be a partial or full repipe rather than chasing leaks one by one. FlowFast Plumbing is a referral service — we connect you with an independent local plumber who can repair the pinhole, assess the system's condition, and give you straight advice on whether repiping deserves discussion.
Warning signs
Signs you need this service
- A fine mist or spray from a copper pipe, sometimes only visible with a flashlight in a dark basement or crawl space.
- Green-blue corrosion crust or tiny wet spots on exposed copper pipe — the telltale pitting that precedes a breakthrough.
- Unexplained dampness inside a wall served by copper lines, with no failed joint or fixture in sight.
- A second or third pinhole appearing months after the first was fixed, signaling a systemic water chemistry problem.
What to expect
The process, step by step
The pro locates the pinhole — sometimes with the line pressurized so the mist is visible — and shuts off water to the section.
The pitted area is cut out with margin on both sides, since corrosion extends beyond the visible hole.
New copper is spliced in with soldered or press fittings, matched to the existing pipe size and type.
The repair is pressure-tested, surrounding pipe is inspected for early pitting, and water chemistry testing is discussed.
Prevention
How to avoid this problem
- Have your water tested for corrosive chemistry — pH, chloramines, and velocity issues drive most pinhole outbreaks.
- Keep water pressure moderate and flow velocities reasonable; excessive speed erodes copper from the inside.
- If pinholes recur, get a repipe assessment rather than patching indefinitely — repeated repairs cost more over time.
Frequently asked questions
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