Pinhole Leak In Your Copper Pipe? This is What You Should Know

Copper is a durable material that often lasts for 20 to 50 years when it is used to manufacture things like pipes. Despite the longevity of copper pipes, they can develop pinhole leaks. Here are a few things that you need to know about leaks in copper pipes.

How Pinhole Leaks Occur

If a copper pipe is exposed to certain conditions, it could form a leak in as little as two years following installation. These types of leaks are common around the country. They form when variants in the water’s pH value wear down a pipe’s natural protection against corrosive elements.

What is the Definition of a Pinhole Leak?

According to a study completed on copper plumbing, a leak is a puncture in copper pipes, fittings or tubes that are used to distribute water domestically.

Pinhole leaks are miniscule. In fact, they are typically smaller than 1/8 inches wide. They also feature a pinhole shape, which is why they have the name that they do. When this type of leak is present, it signifies the final breaking through of a deteriorating corrosion issue that’s been developing on the inside of a copper pipe. This means that the leak is not an origination problem. Instead, it’s the culmination of lengthy corrosive damage.

How Does This Type of Leak Begin?

A pinhole leak is caused by pitting corrosion. This is a localized type of corrosion that results in the development of a hole. This form of corrosion impacts a small section of the pipe. Over time, the small section will gradually wear down until it collapses in and becomes a hole or a pit. Once the hole or pit has fallen in on itself, it’s considered a pinhole leak.

What are the Signs of a Pinhole Leak?

The signs of this type of leak include:

• A higher water bill
• Diminished water pressure
• Damage that you can see
• Mold
• Dripping noises
• Discolored pipes
• Condensation

High Water Bill

Regardless of the leak size, you will see an increase in the cost of your water bill. Take note of your water bill each month and pay attention when you see unexpected changes.

Diminished Water Pressure

Not only will you lose water following a leak, but you will also experience diminished water pressure. Whatever the size of the pinhole, the pressure in the pipe will decrease. This may result in reduced water pressure in every faucet of your home, which is the last thing that you want to have happen in the winter.

Damage You Can See

If you have a plumbing conduit that’s been leaking for a while without your noticing, at some point, damage will develop that you can see. This type of damage is likely to impact the materials that are around or near the leaking pipe. For instance, you may spot wall discoloration if the leak is inside the wall.


Pinhole leaks are known for being the cause of mold and mildew growth. The reason for this is that these kinds of leaks usually form inside a wall. This means that it’s likely for them to continue leaking undetected, resulting in an environment that’s perfect for mold growth.

Dripping Noises

If you hear dripping sounds in your home, then this is a more obvious sign that you have a plumbing conduit that’s developed a leak.


The exterior of a copper pipe should appear to be the color of copper. If you are able to see your pipes and they appear blue, green or brown, then it’s a sign that the plumbing element is starting to oxidize because there is water present.


The exterior of your copper pipes should be dry. They should never appear wet or damp. When copper pipes are wet, then it’s because of a leak or from condensation that’s formed due to a leak. While there are many possible pinhole leak symptoms, keep in mind that these types of leaks are especially challenging to find. The reason for this is that they are miniscule. Also, they may develop anywhere on a copper pipe.

One definite way to check for a leak is by turning off your home’s water supply. Then, check the water meter. If you see the meter shifting after shutting your water off, you have a leak that’s undetected in your home. This method will notify you that you have a leak, but it won’t help you pinpoint the leak location.

What are the Causes of Pipe Corrosion?

There are three main reasons that corrosion occurs, which are:

• Chemical damage or mechanical damage
• Localized damage to the protective coating
• The existence of elements like non-uniformities in the copper

Chemical or Mechanical Damage

The most common cause of pinhole leaks is chemical damage. The pH value of your home’s water has little to do with its safety or quality, but it can impact the copper pipes. According to a study on copper pipe leaks, there are different ways that the pH value can interfere with a pipe’s sulfate content, bacteria, temperature and metal to develop the conditions required to cause damage.

If any of the damaging conditions develop in your home’s copper pipes, then it will cause a chemical reaction that will destroy the pipe’s protective oxide coating. This coating insulates your home’s inner pipe metal against the water that makes its way through them. If the chemical reaction is able to wear away the coating entirely in small sections, then these sections will become vulnerable to the development of corrosion. This is when a pinhole leak may become present.

Mechanical damage may happen from contaminants like sediment or metal that’s present in the water. This kind of sediment may come from a water heater. When these contaminants are present, they may wear down the interior of your home’s pipes as they move through them. This type of damage happens more often when water is especially hard or treated locally. If you have hard water pressure, then it may also wear away a copper pipe’s oxide coating.

Damage to the Coating

While it’s unlikely that your copper pipes were of poor quality, it’s possible that they are defective or were not installed properly. These types of problems happen more often when pipes are retrofitted or installed without professional guidance. If copper pipes become damaged, they may not be able to stand up against corrosion properly. This can lead to a leak or another problem.

Repairing a Pinhole Leak

If you suspect that your plumbing system has developed a pinhole leak, consider contacting a professional plumbing company for a repair. The only way to repair this type of leak is with the sweating replacement technique. While the repair gear that you need is available at the hardware store, it’s best to let the professionals handle this one because the repair involves soldering and expertise.

Preventing Leaks in Copper Pipes

Chemical reaction issues that cause your plumbing to break down generally happen due to high pH value in the water. A water softener may prevent high pH from developing. You may also prefer how a water softener helps your water heater create heat. Check the water pressure meter that’s located on your main water line. The pressure should be from 40 PSI to 60 PSI. You may need to purchase a water pressure limiter to prevent high pressure from harming your pipes if it’s higher than 60 PSI.

A Common Home Problem

Pinhole leaks are a common home problem. The good news is that they’re easy to fix. Be sure to contact a professional company. At Apollo Plumbing, we can help pinpoint leaks in copper pipes and repair them.