Pinholes in Copper Plumbing


Copper plumbing is the one plumbing material that has stood the test of time due to its resistance to corrosion. However, the important word in that description is “resistance.” Copper plumbing, like anything in this temporal world, will corrode eventually, and sometimes it will prematurely corrode in certain conditions. One sign of corrosion is what is commonly called “pinholes.”  These are tiny holes or thin areas that allow water to seep out or even spray out.  Some causes of these tiny little holes can include age, turbulence, the reaction to chemicals in the water source, improper fittings, and high pH levels. 


My job during a home inspection is to visually examine all accessible plumbing after running water through them from the fixtures of the home. During the examination I am looking for corrosion, proper support, & leaks. One of the signs of pinholes is a blue-green discoloration of the copper in various places. These blue-gree dots are not always leaking, but sometimes I get to see the holes actively leaking. Whether they are leaking or not, I report them as thin areas so a licensed plumbing contractor can examine them and make the necessary repairs. Below are some examples of actively leaking pin holes:

Other possible signs of this type of leak is if there is a noticeable change in water pressure, your water bill is increasing, and/or there are stains on the ceiling or wall where plumbing is suspected.

Generally, it is recommended that if your copper plumbing is 20+ years old, and it has pinholes, to replace the plumbing. If the plumbing is less than 20 years old, and there are pinholes, then the cause of the premature corrosion can be investigated and repaired depending on the cause of the corrosion. 


In order to determine if you have pinhole leaks in your copper pipes, it’s important to have them inspected regularly. Contact me today and let me help ensure your plumbing is functioning properly.  When you really want to know Contact Adam Duncan of Duncan Home Inspection Services, LLC.