Running PEX in crawl space

[HouseMedic]

Hi all,
I am thinking of running a Home Run PEX system in my beach house that I am remodeling.(two part modular) All I have is 1 and a 1/2 bath, clothes washer and kitchen sink plus I think I am going to add two hose bibs. All the old galv. pipe has been removed and most of the insulation and bottom covering is off. It is all wood construction. I am going to run a manifold in the closet where the hot water heater is and run individual lines to each fixture with shut offs at the manifold. I guess my biggest question is, I live in Delaware and we get pretty cold winters here. My house is on a 5 block high crawl space with vents and was wondering if I would be taking a chance on pipes freezing in the winter. I am not there much in the winter and the heat is mostly set at around 50-55 degree's in the house when not there. I know that with Pex and a home run set up I can not keep the piping up in between the floor joist with the insulation. I have seen other houses on crawl spaces that have CPVC plumbing and from what I can find out they have not had any frozen pipes and they are exposed. Do you think the temps would be warm enough in the crawl space to keep the PEX from freezing? I know it can take some freezing but I want to try to eliminate that from happening. Also what is you take on putting in copper stub outs at each fixture. The stub outs would have a crimp inside the wall. Any info would be appreciated.

Thanks,
Ron

[Mark]

If the walls of your crawl space are insulated, then you may be OK if your able to route a little heat to the crawl space.

I once ran pipes for a guy in his crawl space. I ended up heat-taping every one of them. I definitely wouldn't recommend that. What a nightmare of heat tapes.

Mark

[HouseMedic]

Thanks for your reply Mark. If I use more crimp connections I could keep the lines mostly up in the floor joist. But with the heat ducts I don't think I can keep the lines up above them. How close can PEX run over a heat duct. The ducts that I have are running across the floor joist. My original plan was to keep the plumbing up in the joist then insulate then cover with a type of belly material. The thought of more connection sort of defeats the purpose of running a home run system. Also has anyone ever heard of mice eating at PEX plumbing? I have seen on some web forums about this happening.

Thanks,

Ron

[JD]

We usually run PEx beside the ducting where ever possible and up in the floor joists always. I really don't deal with freezing problems though, so I really don't have experience with that. Depending on the crimp rings you use, I would be concerned about metals touching. Copper and aluminum can do some strange stuff when left together for a long time.

I have never heard of mice chewing PEx, but I have seen them chew other plastics and harder materials.

JD