> **Must** these old pipes be replaced?

No, unless your town has a code which states that galvanized plumbing must be replaced during an opportune time such as a remodel.

Should you? Yes. Don't wait for a **must** situation or else you'll be replacing a lot more than just pipes. Consider everything below your bathroom trashed.

My house was built in 1940 and 2 years ago I replaced all of the the downstairs galvanized water pipes with PEX; cost about $900. Once I'm ready to tear into the second floor you can bet your last dollar that I'll be replacing the galvanized pipes.

When removing the old galvanized pipe I was curious as to how difficult it is to unscrew these joints as opposed to using my sawzall so I grabbed some pipe wrenches and twisted a tee right off; the threads were left inside of the tee.

This particular joint would probably have failed in the next few years. It was rusted down to a pinhole about 1/8" in diameter and was the source of terrible hot water flow for our kitchen and upstairs bath.

Rust begins life on the inside of the pipe and if you start seeing surface rust that that means it has breached the entire wall of the pipe.

Make note of the water leak from the rust spot on the right.

[![Galvanized water pipe rusted from the inside-out and is leaking][1]][1]

[Source][2]

  [1]: https://i.sstatic.net/rfXOw.jpg
  [2]: https://howdyinspections.com/wp-content/uploads/2015/08/Galvanized-Plumbing-Pipes.jpg