cross-linked polyethylene tubing and rodents

[calvert]

I had a meeting today with a mechanical contractor to discuss his proposal to replace a rather antiquated heating system at a large house that I do restoration work at.

We had a preliminary meeting about three weeks ago and during that session I asked what supply line piping he would use for the new hot water system. He was fairly sure that pex would be the choice for the runs from the new boilers to the air handler coils.

In our meeting today he strongly suggested copper based on the fact that most of the runs in our system would be in a crawl space and he is concerned that rodents might chew into the lines if done in pex.

The structure is nearing 100 years and is in a rural setting. Although I have never seen evidence of excessive rodent activity this was a concern of mine when I first saw pex being used ...however many years ago.

The mechanical contractor said that in the last 2 weeks they repaired 3 pex water lines in houses that were chewed into by some form of rodent. I know mice and squirrels can chew the heck out of pvc covered wiring.

Anyone have experience with such occurrences?

[tomthetoolman40]

Re: cross-linked polyethylene tubing and rodents

I've never seen rodent damage to pex or the grey (poly butyl?) used in mobile homes. I have seen lots of the mobile home fittings (the crimped on ones) fail, so that is a consideration since the pex uses crimp-on fittings.

[wfoconstruction]

Re: cross-linked polyethylene tubing and rodents

20111230102501.jpgHad a huge rat hit my parents house last winter and chewed through the pex in three different locations of the house, lines were run between first and second story. This is a rural area also and it was a field rat. First time I and any plumber I've talked to said it has happened and I hope it never happens again because pex is all we use...

[calvert]

Re: cross-linked polyethylene tubing and rodents

Wfo, thanks for that. Is that guy alive or not so much?

Alas, the question now becomes, do they do it because it's tasty to chew on or do they sense water in the pipe?

Did you suffer any severe damage from the leaks?

[newman]

Re: cross-linked polyethylene tubing and rodents

perhaps they should have a ss braiding on those PEX lines?
I'm always worried about rodents too!

[Marven]

Re: cross-linked polyethylene tubing and rodents

I think most rodent damage is done by mice trying to get from one floor to another. They know there is a hole there and chew into the pex to get through. They sell sleeves that will protect the hole and the pex from mice.

[Scott Jameson]

Re: cross-linked polyethylene tubing and rodents

<> question now becomes, do they do it because it's tasty to chew on or do they sense water in the pipe?<>

Tasty gets my vote.
Rodents chew vinyl insulation from electric cords, too.

[kfc510]

Re: cross-linked polyethylene tubing and rodents

Tasty gets my vote.
Rodents chew vinyl insulation from electric cords, too.

Maybe both? But they do like to chew on plastic. Here's a pic of my old clipboard/box with the calculator at the top. Santa Fe mouse got after it one day.

(At some point I doodled a bit and put pencil marks on the tooth-made grooves on some of the key stubs to the right, but the grooves themselves are all the work of li'l squeaky.)

[slomoe]

Re: cross-linked polyethylene tubing and rodents

To tomthetoolman: most of the pex I see run toady is has a collar and is expanded and then slipped onto the fitting. Once the pex contracts, and if the fitting was slipped into the pex to proper depth (the shoulder on fitting), I haven't seen one fail. I think the crimp on stuff was early tech when pex came out, but I'm not sure if it still being used?