PVC, copper or galvanized in crawlspace


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Old 10-26-06, 01:34 AM
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Question PVC, copper or galvanized in crawlspace

I'm remodeling an old house and have gutted the old plumbing. It used to have galvanized pipe in a small crawlspace (about 1' to the joist bottoms). The sub-floors and drywall is removed in the bathroom and kitchen. So I have easy access for now. Question is, what type of pipe should I use, knowing there will be no (or very limited) access in the future.

As I see it, pvc/cpvc may be the best option. Copper tends to get pinholes over time if the water is acidic... even K grade. Glavanized tends to clog with corrosion. All of the old pvc pipe I've seen looks almost new inside and I've never had a leak.

My biggest concern is freezing in an unheated, uninsulated crawlspace. I was thinking of running everything I can with the floor joists and adding a layer of insulation and maybe a cover plate (metal flashing?) below that for a wind break. Where I have to go across or through joists, maybe I can build some type of insulated raceway as close to the flooring as practical. I even considered installing a couple floor vents to that space to keep it warm.

Option two is running most of the pipe through the walls. Maybe not so good an idea should there be a leak.

Most of the houses in the area have galvanized pipe. So I know it holds up well to crawlspace conditions. How does PVC hold up in comparison? Any installation suggestions?

Thanks
 
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Old 10-26-06, 06:39 AM
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I've never, ever considered PVC for supply lines inside (to the sprinkler system, maybe) and am not even sure it meets code requirements (I don't believe it does - but since I've never considered it - I've never checked). PVC is to brittle.

After repiping a new addition in Colorado last year, PEX is now my material of choice (again, check your local codes for acceptance) - as it is not as susceptible to breaking if it freezes - it's easy to install - and, overall, not much more spendy than traditional copper. Galvanized is a pain in the A _ _ - as all your bends/runs have to be measured carefully, pipes need to be threaded - and repairing future problems is difficult, if not impossible. Copper is traditional and easy to work with, withstands some freezing, and relatively inexpensive.

I just bought a 80 yr old home with a crawlspace under a portion of the house, with supply lines running through that portion - and the previous owner put in a heating duct to the space, with a on/off baffle in the ductwork to avoid cooling the space in the summer. (smart guy)
 
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Old 10-27-06, 12:41 AM
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Thumbs up

Thanks for the response Thezster.

I checked with two supply houses. Neither recommended PEX. Both recommended copper for a crawl space. Then I realized neither stocked or really understood PEX. Turns out they both dealt almost exclusively with commercial construction. They said PEX isn't allowed in commercial construction due to fire ratings.

So, I took a trip to Lowes. The guys there love PEX. They referred me to a local plumber that uses it. Evidently, most local plumbers won't touch it. The Lowes guys' theory was that it puts plumbers out of a job since most homeowners can't sweat copper, but they can do PEX themselves. Hopefully, this plumber will be kind enough to offer some tips and recommendations. The PEX system and reliability look great to me. Other than buying the crimp tool, the cost does look similar to copper.

What is everyone's experience with the push type PEX connectors rather than the crimps? They just don't look as reliable as crimps to me. Guess I'll be spending $173 on a multi-crimp tool (or $109 for each size crimper).

Thanks again Thezster. I think I'm on the right track now.
 
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Old 10-27-06, 04:34 AM
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Do what I did... buy the crimping tool - and finish your job completely - then sell it for a profit on E-Bay (I actually got $5.00 more than I paid for it brand new). PEX is sooooo easy to work with that I almost threw out my soldering torch. All the materials are available via the internet (if your local supply house won't sell to you, which is what happened to me). If I ever do extensive supply plumbing again - and local code allows it - it will be PEX.
 
 

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