While many newer homes use PVC piping, copper piping is still extremely common in many houses. If you live in a home with copper piping, then you may have had to deal with corroded pipes or you may be concerned about dealing with them in the future. Corrosion in metal pipes is a major issue that can cause the pipes to leak and eventually fail completely. Often, corroded pipes become a chronic issue. Since water will always attempt to find the path of least resistance, fixing one leak can simply cause a new leak to spring up a few days or weeks later in another weakened section of pipe.
This pattern of leaks and repairs can be frustrating, and leads most homeowners to replace large sections of piping. But why are those pipes corroding in the first place?
Corrosion is a process by which a metal, such as the copper in your home's pipes, is gradually broken down. From a chemical perspective, the metal is actually moving towards a more stable long-term state. For metals that are not extremely resistant to corrosion, this happens because the bonds between metal atoms are weaker than the bonds between a metal atom and an oxygen atom. This process results in many metals being stripped of their electrons, ultimately resulting in a more stable oxide.
Of course, the fact that this is what is known as a favorable chemical process does not mean that it's something you want in your home. Corrosion destroys pipes, weakening them until abrasion from the water running through them is enough to create a leak. This is definitely not something that you want happening to your plumbing.
Causes in the Home
Copper is actually fairly resistant to corrosion, but there are a number of circumstances that can cause your copper pipes to corrode more quickly. Even worse, once corrosion begins, it is often too late to save the affected sections of pipe. Seemingly good pipe must often be replaced alongside clearly damaged pipe simply because the interior of the pipe is already corroding and will likely fail soon.
The most common cause for this type of corrosion is acidic water. Acidic water has a high concentration of dissolved oxygen or CO2. This exposes your copper pipes to a higher concentration of oxygen than they would be exposed to otherwise, rapidly accelerating the corrosion process.
In other cases, mechanical wear is at fault. Water that is traveling too quickly for the pipe size or the presence of gritty materials can wear down the pipe from the inside. This kind of mechanical wear is more accurately referred to as erosion, but it relies on corrosion to wear the pipe out quickly. In other words, the existence of corrosion within the pipe allows mechanical action to wear it out more easily.
Finally, corrosion can actually be caused by electrical faults. If an improper ground runs through a copper pipe, it can greatly increase the rate of corrosion. In fact, electrical issues are often the most likely culprit when an another otherwise healthy pipe suddenly becomes to corrode rapidly.
Short- and Long-Term Solutions
For a short-term fix, there's really nothing that can be done aside from replacing the corroded section of pipe. Many homeowners opt to repair simply the one section that is leaking, but if corrosion has taken hold then the problem is often much larger. Many plumbers will recommend replacing a large section of pipe near the leak, but even this is a temporary fix at best. Other sections of corroded pipe inevitably exist, and eventually water will force its way through those areas as well.
For a longer-term fix, the source of the corrosion must be identified. This can be a difficult task, so it's best to check with plumbing contractors and have them perform this diagnosis. Once the reason of the corrosion is found, it can be dealt with directly. In some cases, replacing your copper piping with PVC piping may be the only option. In other cases, it may be possible to solve the source of the corrosion and save your pipes. Whatever the case, dealing with corrosion promptly is important to avoid facing a never-ending deluge of leaky pipes.