What Causes Corrosion on Interior Pipes?

Are you wondering if the pipes in your house are corroding? It can lead to serious problems and may require a complete repiping of your entire house. Learn why your pipes are corroding, what you can do to slow down or prevent corrosion, and what to watch out for when your pipes get older.

How can I prevent pipe corrosion?

Multiple factors can often exacerbate problems with the integrity of pipes. Older plumbing systems can be more susceptible to corrosion than modern systems, but even newer pipes may show signs of corrosion up to two years after being installed if there are the right conditions. It is possible that you may be surprised at some of the causes. Some of the factors that exacerbate corrosion are, for example, the chemical composition of some of America’s cleanest water sources. Additionally, drain cleaners have a reputation for being extremely harsh on pipes and causing them to corrode.

These are some of the most common reasons for corrosion.

Low pH

The pH of water is measured in Ph. It can be anything from zero (most acidic), to 14 (most alkaline). The neutral pH is 7 pH.

Copper pipes should be monitored for pH. Your pH should be 8 or more (more acidic than alkaline), and copper oxide can form inside your pipes to slow down or minimize corrosion. If your pH level is between neutral and acidic, however, copper oxide barriers will dissolve, making your copper pipes more susceptible to rapid corrosion.

How can this happen? What happens if there are pinholes in the copper pipe plumbing system?

Oxygen + Water Temperature

The oxygenated water in your water is continually replenished. This means that oxygen has been dispersed into water. It is composed of about 30% oxygen and 70% Nitrogen. While nitrogen is not corrosive, oxygen can corrode metal through an oxidation process.

When the metal becomes oxide (rust), it begins to corrode and then the metal starts to thin and become less strong as the rusted metal grows. Three things occur as corrosion progresses.

The water velocity is too high

A “closed-loop” system of piping can lead to erosion-corrosion. This is a term I know but it is real. It may be caused by flow obstructions like excessive solder if the joints weren’t properly soldered.

Chemical drain cleaners

Although they may be able to cut through the blockage in your pipes with chemical drain cleaners, they can also cause damage to pipes. To understand the reasons why chemicals drain cleaners can be so harmful to your pipes, and which types of drain cleaners will work best for you, please see our article on what drain cleaners to avoid.

Schedule Your Free Estimate