>Q: I own several apartment buildings, ranging in age from 20 to 50 years old. During the last couple of years they have been plagued by pinhole leaks in the copper plumbing, mostly around the joints. What causes these leaks to occur?
A: Corrosion and leakage in copper plumbing pipe is a more common phenomenon than is generally considered. It can occur in older installations, like yours, as well as in relatively new systems.
Though copper piping has an expected service life of 20-50 years, it is not considered a “permanent” plumbing supply system. Actually, nothing is. Where copper pipe fails along that time line (or before) can depend on several factors. In your case there might be a combination of troubles all coming together at once – age of the pipes, possibly aggressive water, possible problems with the flux used in the soldering process, and maybe a couple of more obscure things as well.