What Causes Pipe Corrosion and How to Stop It

Pipe corrosion is a common plumbing problem that can lead to leaks, water damage, and expensive repairs. If you understand what causes corrosion and use effective solutions, you can protect your home’s plumbing system and avoid major issues.
What Is Pipe Corrosion?
Pipe corrosion happens when metal pipes slowly break down because of chemical reactions, usually from water, air, or certain minerals in the water. Over time, this weakens the pipes and can cause them to crack or leak.
Common Causes of Pipe Corrosion
Oxygen in Water
When water contains oxygen, it can react with the metal in pipes and cause rust. This is especially a problem in hot water systems, where high temperatures speed up the process.
Acidic Water (Low pH)
If your water has a low pH (meaning it’s more acidic), it can wear away the protective coating on pipes. Once that layer is gone, the metal underneath starts to corrode.
High Water Speed
Water moving too fast through pipes can cause something called “erosion corrosion.” This means the force of the water scrapes away the inside of the pipe, leading to thin spots and holes.
Harsh Drain Cleaners
Some chemical drain cleaners are very strong and can damage your pipes if used too often. They might clear a clog fast, but they also speed up corrosion.
Minerals in the Water
Minerals like chlorides and sulfates, found in some water supplies, are especially rough on pipes. They can create tiny holes or pits in the metal, which grow over time and lead to leaks.
For more about how water chemistry affects corrosion, you can visit this helpful guide from PHMSA.
Simple and Effective Ways to Prevent Pipe Corrosion
Use Cathodic Protection
This method uses another piece of metal, called a sacrificial anode, that corrodes instead of your pipes. It’s commonly used for outdoor or underground metal pipes.
Add Corrosion Inhibitors
Some water treatment systems can add chemicals that coat the inside of pipes. These chemicals act like a shield and help prevent rust or corrosion from starting. Adding chemical inhibitors to the water can form a protective film on the interior surfaces of pipes, shielding them from corrosive substances. This approach is common in industrial settings and can be tailored to specific water chemistries.
Balance Your Water’s pH
Water that’s too acidic or too alkaline can damage pipes. A plumber or water treatment expert can help test and balance your water’s pH so it’s safe for your plumbing. Maintaining a neutral pH in the water supply helps preserve the protective oxide layers on metal pipes, reducing the risk of corrosion. This can be achieved through water treatment processes that adjust the pH to optimal levels.
Check and Maintain Your Pipes
Inspect your plumbing regularly for signs of rust, leaks, or strange-colored water. Catching corrosion early means you can fix it before it gets worse.
Use Corrosion-Resistant Pipes
If you’re installing new pipes or replacing old ones, choose materials that don’t corrode easily, like PVC, PEX, or stainless steel. These materials last longer and don’t react with most types of water. Using pipes made from materials less susceptible to corrosion, such as PVC, PEX, or stainless steel, can significantly extend the lifespan of plumbing systems. Material selection should consider the specific environmental conditions and water chemistry.
Final Thoughts
Pipe corrosion doesn’t happen overnight, but if left unchecked, it can lead to serious plumbing problems. Knowing what causes corrosion and using smart, simple fixes can keep your plumbing safe and strong for years. If you’re unsure about your pipes or water quality, it’s a good idea to talk to a professional plumber.
