Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I am living in an old building where the old galvanized steel pipes are still in use indoors.

Rather than upgrading to copper pipes, can I reuse these galvanized steel pipes for hot water (from a gas heater for showering)?

I have the impression that galvanized steel pipes are very vulnerable to corrosion when used with hot water. But I don't want to change to copper pipes because some of the galvanized steel pipes are conveniently available next to my gas heater hot water outlet.

share|improve this question
You'll have to inspect the pipes first, often this is what old galvanized pipes look like inside. – Tester101 Apr 27 '12 at 11:43
Thx, Tester101, the galvanized pipes are embeded inside the wall so it is difficult to replace it. I'd prefer to reuse it if possible. – JavaMan Apr 27 '12 at 11:46
I'm having a hard time finding good citations, but: it is thought that hot water affects the galvanized coating and increases the rate of corrosion and build-up inside the pipe. Galvanized pipe is apparently no longer allowed by code in Canada for (treated?) potable water (inside, anyway). Depending on the chemical composition of your water (pH, dissolved minerals) it may react with the pipe, causing other contaminants (a concern mostly if you are not on city water). Though you don't typically drink shower water, it does get absorbed into your skin and dispersed into the air (and your lungs). – gregmac Apr 27 '12 at 21:40
@gregmac This link agrees with your comment on increased corrosion and build up in the pipe, also as a side point it mentions the problem connection copper to gal eg new hot water pipe to old. – UNECS Apr 28 '12 at 6:22
We're using city water in our properties and every one that has galvanized pipes are just as corroded and gummed up as the picture posted by Tester. – The Evil Greebo Apr 28 '12 at 14:11

If you have the opportunity to replace your galvanized pipes, do so. It's an inconvenient project, involving opening up a lot of walls, but as you can tell from the comments, galvanized pipe is problematic at best over the long term.

It will frequently develop (as is the case in my own home and in my rentals) pin hole leaks. The only good news with galvanized on that front is - the gumming will often re-seal those pinhole leaks, but not all the time, as my basement ceiling could have attested, before I gutted the whole thing.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.