Noticing a greenish stain around a pipe fitting or a metallic taste in your water is a sign that your copper pipes may be corroding, and it’s worth understanding why before the damage worsens. Knowing what causes corrosion in copper pipes helps you address the root problem rather than just patching symptoms. In this guide, Feltner Sewer & Drain will explain the science behind corrosion and what to do once it starts.
If corrosion has already caused damage, speaking with professional plumbers is a good next step.
Looking at the Science Behind Corrosion
Copper pipe corrosion is an electrochemical process that happens when copper reacts with elements in the surrounding water. Copper is generally durable, but it isn’t immune to chemical attack, particularly when water conditions are aggressive. Understanding the different types of plumbing pipes helps put copper’s strengths and vulnerabilities in context.
Why Do Copper Pipes Corrode?
Several specific factors drive corrosion in copper pipes, and more than one may be at work at the same time. Here are the most common culprits:
- Low pH levels: Water with a pH below 7 is acidic and corrosive to copper, accelerating the breakdown of the pipe’s inner surface and contributing to premature failure.
- Dissolved oxygen: Elevated dissolved oxygen levels increase the rate of copper pipe corrosion by reacting with the pipe surface and accelerating oxidation, especially in hot water systems.
- Pitting corrosion: This localized form of attack creates small, deep pits in specific spots on the pipe wall, and it’s particularly dangerous because the pipe can look intact while a pinhole leak develops inside.
- Water chemistry imbalance: High chlorine levels, elevated sulfates, or aggressive minerals can all contribute to a water chemistry imbalance that breaks down copper over time.
- High water velocity: Water moving too fast can physically erode the inner copper surface, most often at elbows and fittings.
Can You Prevent Pipe Corrosion?
Prevention is more effective than repair once corrosion is established. Having your water tested regularly gives you a clear picture of pH, dissolved oxygen, and mineral content so you can take targeted action before damage occurs.
If low pH is the issue, a whole-house acid neutralizer filter can raise the water’s pH and protect the pipes. In older homes with known corrosive water conditions, periodic pipe inspections help catch developing problems early.
How To Repair It Once It's Started
Minor corrosion that hasn’t caused leaks can sometimes be slowed by correcting the water chemistry and flushing the system. Once pitting corrosion or active leaks are present, the affected pipe section typically needs to be cut out and replaced. Epoxy pipe lining is another option in some cases, where a resin coating is applied to the interior to seal minor corrosion and prevent further water contact with the copper.
For widespread corrosion in an older home, full repiping with copper or an alternative material like PEX may be the most practical long-term solution.
Feltner Sewer & Drain Helps You Get Ahead of Pipe Problems
Understanding what causes copper pipe corrosion puts you in a better position to protect your plumbing before minor wear turns into a major flood. At Feltner Sewer & Drain, we accurately diagnose deteriorating lines and provide the reliable pipe repair services you need to address the root cause.
If you’ve noticed your pipes making noise, it can sometimes be related to pressure or velocity issues that also contribute to corrosion. We provide comprehensive drain, sewer, and pipe services for homeowners. Call Feltner Sewer & Drain at (866) 312-4018 for help with corrosion in copper pipes.
Frequently Asked Questions
Here are answers to common questions about copper pipe corrosion.
How Do I Know if My Copper Pipes Are Corroding?
Signs of copper pipe corrosion include blue-green staining around pipe joints or fixtures, a metallic taste in tap water, pinhole leaks, and discolored water.
Does Hard Water Cause Copper Pipe Corrosion?
Hard water can actually form a protective mineral scale inside copper pipes in some cases, but certain mineral combinations or high chloride levels can still contribute to corrosion over time.
How Long Do Copper Pipes Last Before They Start Corroding?
Copper pipes typically last 50 years or more under normal conditions, but aggressive water chemistry, high water velocity, or installation issues can shorten that lifespan considerably.
What Causes Corrosion in Copper Pipes in Older Homes?
A combination of decades of exposure to poor water chemistry, age-related thinning of pipe walls, and outdated installation practices can leave pipes more vulnerable to corrosion. If you live in an older home, it’s important to have your pipes inspected regularly.
