Why Do Copper Pipes Turn Green Over Time?
Copper pipes naturally react with oxygen, water, and certain chemicals over time, causing a green patina to form on the surface of the pipe. This process, called oxidation, is the same reaction that turns copper roofs and statues (such as the Statue of Liberty) green over decades.
A greenish hue does not always mean your plumbing is failing. In fact, a mild patina can actually protect the metal beneath from further corrosion. However, rapid or uneven discoloration is a telltale sign of excessive corrosion or water quality issues.
Older copper pipes tend to show more pronounced green patches, especially if they've been exposed to moisture or contaminants over time.
What Causes Copper Pipes to Develop a Green Patina?
- Oxidation from water exposure: Copper reacts with oxygen and water minerals, forming green copper salts like copper carbonate or copper chloride.
- Corrosive water properties: Water with high acidity or hard water containing calcium and magnesium can accelerate surface corrosion.
- Debris and sediment: Particles like sand or grit in the water can rub against the surface of your copper pipes, allowing corrosion to occur more quickly.
- Environmental factors: High humidity, leaks, or plumbing near exterior walls can encourage quicker oxidation.
Over time, these factors might create small pits or weak spots in the pipe, which may eventually lead to pinhole leaks. Monitoring for green stains, white residue, or wet spots near your home's copper pipes can help catch these issues early.
Are Green Pipes a Sign of Pinhole Leaks in Copper?
While a green patina alone isn't always a cause for concern, it can sometimes indicate more significant underlying issues, such as pinhole leaks. These leaks are small, localized holes in the copper pipes that allow water to escape slowly.
Some common signs that your green copper pipes may be leaking include:
- Water stains or discoloration around baseboards, walls, or ceilings.
- Low water pressure in faucets or showers.
- Sudden increases in water bills, even with normal usage.
- Mold or mildew growth near plumbing lines, indicating persistent moisture.
Pinhole leaks are often the result of internal pitting corrosion, which is accelerated by water chemistry, high flow velocity, and aging copper pipes. Older or lower-quality copper piping is especially susceptible, making early detection critical.
How Do You Repair Pinhole Leaks in Copper Pipes?
If you discover pinhole leaks in your copper plumbing, temporary solutions like pipe clamps, epoxy putty, or replacing small sections of pipe can provide a short-term fix. However, these solutions do not address the underlying issues in your piping system and often only delay the inevitable: recurring systemic leaks.
For a reliable, long-term solution, we always recommend a full home repipe, especially if you've experienced multiple pinhole leaks in your copper plumbing. Replacing aging copper pipes with PEX (cross-linked polyethylene) tubing helps increase your home's fresh water lines' resistance to common issues such as corrosion, scaling, and pitting.
PEX piping is highly flexible, allowing for easier installation and reducing the number of joints in your plumbing system. Additionally, PEX has a long lifespan and can remain leak-free for decades, making it a cost-effective and low-maintenance alternative to aging copper pipes. For more information, see our article about why you should repipe with PEX.
At Repipe Specialists, we use Uponor PEX-A tubing alongside Type L copper pipes with all our repipes, depending on your personal preference. We help ensure that your home's plumbing system is both reliable and built to last by addressing the root cause of pinhole leaks.
Contact us to have one of our local repipe consultants explain your aging copper repipe options and provide a consultation and quote, either in-home or remotely.
Get your free estimate today
With over 75,000 repipes completed, we've perfected our One-Stop Repipe™ for your home.
Get a Free Quote to Replace Damaged Copper Pipes
Here at Repipe Specialists, we've fully replaced the plumbing in over 60,000 homes since 1991. A Type L copper or Uponor PEX-A repipe is a long-term investment that can save you money for years to come. We consistently receive positive feedback from homeowners about their overall repipe experience and often exceed expectations when it comes to:
- Speed: Our repipe crews typically complete a repipe in a day, returning on another day for wall patching.
- Convenience: Through our One-Stop Repipe™ process, we handle everything from permits, to wall patching, to inspections.
- Cleanliness: Our crews are trained to protect your home while working (we cover all surfaces with protective sheeting), and to clean up fully at the end of each day.
- Peace of Mind: Repipe Specialists is a fully licensed plumber in every state we operate in, and we back all of our repipes with a lifetime warranty.
- Financing programs: To help take the sting out of unplanned repipe expenses, we offer several financing programs.
- Price: As a specialist that performs hundreds of repipes a week, we can deliver high-quality repipes at a lower cost vs generalist plumbers. Our quotes typically range from $4,500 to $15,000 depending on the size and complexity of your project. We have an article that covers repipe cost factors in detail.
Schedule a free in-home consult, and one of our local repipe consultants will explain all your copper repipe options and provide you with a written, fixed-price quote.