Since the era of post-World War II, copper has been the material of choice for residential and commercial water pipes. Copper is easy to work with in manufacturing and during installation. It is also a healthier material for distributing water compared to lead, which had been used for centuries.
Copper pipe is durable, lightweight, and long-lasting but not perfect. It’s prone to pinhole leaks and leaching.
Copper Leaching Into Water
With copper pipes, there is a small risk of copper leaching into drinking and other household water. But it is not the pipes themselves that cause leaching; it’s corrosion.
In unscientific terms, corrosion is the deterioration of the copper. As the copper “dissolves”, particles are released (leached) into the water flowing through the pipe.
The three most common causes of corrosion that lead to leaching are:
Pure water has a pH of 7. If the pH level goes below 6.5, water is considered acidic, or “soft”.
Soft water is low in calcium and magnesium. One of the benefits of soft water is that it doesn’t leave calcium deposits inside water pipes. But it can also cause copper to oxidize. The tell-tale sign of oxidized copper is a blue tint.
Water with a pH of 8.5 or higher is alkaline, or “hard”. Hard water has high mineral counts, especially calcium and magnesium carbonates.
If you’ve ever had lime scale build up inside your kettle, you have seen a downside to hard water. That kind of deposit can form inside copper pipes and eventually cause corrosion.
High Oxygen Levels
The more undissolved oxygen there is in water, the greater the risk of corroding copper pipes.
Of course, oxygen is present in all water (H20). But when water is cold, the oxygen stays dissolved. The hotter the water gets, the more the oxygen can “float away” and attach itself to the copper, oxidizing it.
Like with soft water, increased oxidizing sets the stage for corrosion.
How Strong Is Copper Pipe?
Copper is quite strong. When used to manufacture water pipes, the metal is rigid and durable.
But that doesn’t mean it’s invincible. As explored in the section above, copper can corrode. And wherever there is corrosion, the pipe becomes weak and leaks can develop.
Holes in copper pipes start small, like a pinhole. Depending on the method used, fixing a pinhole leak can be costly.
How To Fix Copper Pipe
Patching a water pipe is the fastest way to stop a leak. It’s a short-term solution that buys you time to find a plumber to provide permanent repair.
Depending on the size of the hole, the patch can be made using plumber’s repair tape, a plumber’s patch kit, or epoxy plumbing putty. Each can be found at hardware and home improvement stores. In addition to directions for use, packages list if the product is safe for pipes that carry drinking water.
To repair a leaky copper pipe, you have two choices:
- Epoxy liner
If a copper pipe has burst, replacement is the only option. But replacement can also be done for holes of any size.
Replacing copper pipe requires exposing the leak. To reach the leak and have enough room to work, several feet of wall, celling, or floor will need to be removed.
The damaged section of copper pipe can be replaced with new copper or plastic pipe. If the replacement pipe is copper, solder is used to connect the old and new sections. Connecting plastic and copper pipes requires a special adhesive.
Compared to replacement, repairing a pinhole leak with an epoxy liner is often a more cost-effective and less disruptive solution:
- The plumber needs less room around the leak, which minimizes the cost and mess of cutting into and restoring the wall, ceiling, or floor.
- All water distribution pipes are dried and sandblasted clean, removing corrosive build-up throughout.
- The epoxy is flowed through the full length of pipe, creating a liner that lasts 40-60 years, saving you from the cost of future repairs.
- The copper epoxy liner is stable in hot and cold water so no chemicals leach into the water supply.
Alternative to Copper Pipe
Copper is the most popular material for water pipes, especially in residential construction. But there are other options.
Galvanized steel pipes are durable but are prone to mineral build-up and corrosion from zinc and iron in tap water. They can also discolor water and give it a metallic taste.
If you want plastic pipes, there are several kinds to choose from: PVC, chlorinated PVC (CPVC), polybutylene (ABA or ABS), polyethylene (ACS) and cross-linked polyethylene (PEX). The types of approved plastic water pipe vary, depending on the regional building code.