Quick answer
Green or blue deposits, dampness, pitting and repeated pinhole leaks can be signs of copper pipe corrosion, but colour alone does not confirm the cause. Do not scrape or disturb a suspect pipe; arrange an inspection if it is damp, weakened or leaking.
Signs to look for
Copper pipe can develop green or blue deposits, particularly around joints, but these may have several causes. More important warning signs include persistent damp, visible pitting, a pinhole leak, staining on nearby surfaces or repeat failures in the same pipework. Corrosion can be hidden inside walls or beneath floors, so visible sections may not show the full condition.
A green mark on an otherwise dry pipe is not by itself proof that the pipe is about to fail. Avoid scraping deposits away, as this can damage weakened metal or remove useful evidence. Photograph the area and note whether it changes or becomes wet.
What can contribute
Corrosion can relate to water chemistry, pipe condition, contact with other materials, installation details or local environmental conditions. The cause cannot be reliably identified by colour alone. A leak at a joint may be due to a fitting or seal rather than corrosion in the pipe itself.
If pipework runs through a damp or concealed area, moisture may also come from another source. A plumber can inspect accessible sections and assess whether further investigation is needed to locate a hidden leak. TraceFix provides leak detection in Birmingham and London, including investigation of concealed water ingress.
What to do if you find a problem
- 1If the pipe is actively leaking, protect nearby belongings and turn off the water at the stopcock if it is safe and accessible.
- 2Keep water away from electrical fittings. If water is near electrics, do not touch them; isolate the affected circuit at the consumer unit only if safe.
- 3Take clear photographs and record when you noticed dampness or a change in water pressure.
- 4Arrange a plumber to assess a wet, pitted, repeatedly leaking or visibly weakened pipe. Do not patch it with tape as a lasting repair.
Inspection and repair
The appropriate response may be a local repair, replacement of a section or broader work if multiple areas are affected. The decision depends on access, pipe condition and the source of any corrosion. A professional should explain what has been found and whether adjacent pipework needs checking.
When to call a plumber
- Copper pipe is actively leaking or has visible pitting and dampness.
- There have been repeated pinhole leaks or repairs in the same area.
- Water staining appears near concealed pipework.
- You cannot safely isolate the affected pipe or water is near electrics.
Common questions
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