Plumbing and Piping - Is it better to route pipes through crawlspace or attic?

I’m replumbing my house with PEX. One story on crawlspace. The current galv pipes run in crawlspace. Would it be better to route the new pipes through the attic instead of the crawlspace?

As far as leaks go, I was thinking that a leak in attic would do more immediate damage but would likely be detected much sooner. Leak in crawlspace could go on for months unnoticed.

But, I'd rather have a slow leak (or burst for that matter) leaching into the ground in my crawlspace than dripping in my living room.

Where do you live? If freezing is a possibilty, routing water pipes through unheated spaces isn't a good idea?
Doug

My brother used to live in Houston, where freezing is pretty rare. However, it is a certainty eventually and this proved true in his house. Mucho damage. Crawl space is much preferable.

Almost all pipes that freeze in Houston are in the attic because back in the 60's they started building them on slabs so they would flood easier. Only in the last few years has it occurred to the builders that a house two feet off the ground doesn't flood as easy as one six inches off the ground. Trouble is the plumbers are so use to putting the pipes in the attic they still put up there rather then underneath.

Guess in another twenty they will figure that out and houses will be back to the way the old timers built them. High enough not to flood in a heavy due and pipes underneath where they belong. Where do you live? If freezing is a possibilty, routing water pipes through unheated spaces isn't a good idea?
Doug
Doug :) You mean they heat attics where you are? They sure don't here.

Hi, Your post states the galvanized pipe is in the crawl space. My reading on these forums indicate pex handels a freeze better that metal pipes. So alas with metal pipe in the crawl space now, freezing should not be a problem. Another advatage of putting pex in the crawl space is the metal pipe will lay it out for you and possible provide support for the pex.
Good Luck Woodbutcher

:) You mean they heat attics where you are? They sure don't here.
No, where I live in the Midwest, I would not classify either attics or crawl spaces as heated spaces. I wouldn't put water pipes in either one. Nor in outside walls, even if behind insulation. Even "frost-free" sillcocks are running a risk.

We still don't know where the originator of this thread, "ThomasE," lives. I wonder why he is re-plumbing his house?
Doug

My reading on these forums indicate pex handles a freeze better that metal pipes.I don't have experience with PEX resistance to damage due to freezing. PEX is less commonly used in this area.

I do believe that steel pipe is much less likely to rupture due to freezing than is copper pipe. I'm not sure exactly why, since copper is relatively ductile. But I've seen copper pipe split open like a hot-dog bun while steel is unaffected.
Doug

Galvanized piping is very resilient to bursting in cold temperatures.

They can be thawed as well electrically.


When pex freezes there is nothing you can do until it thaws. PEX will burst in short sections between fittings but not on the long runs.

There is a case study of this testing that's been on the internet for years...

Personally I'd rather have to work up in a ceiling before a crawlspace, any day. But that's a plumber's perspective.