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Frozen PEX. :(

Kahooli Member Posts: 112
edited January 2018 in Plumbing
The water to my bathroom (which is half over an unenclosed porch) froze last night. I had taken pictures of where the plumber ran everything so I knew where to cut the drywall. Much to my surprise the contractor had neglected to insulate anything in the exterior wall cavity that the supply and drain pipes run in. The horizontal pipes are on the inside part of the the ceiling over the hallway in between the joists. It's amazing how fast (less than a couple minutes) that the pipes thawed and water started flowing after I cut a 6" x 3ft piece of drywall out on the horizontal, and 12"x9ft on the vertical. No leaks currently.

So what's a gent to do? Aside from fixing the insulation and cold air intrusion that froze them in the first place - Do I hope that it doesn't fail? Do I replace everything I can access? I'm looking for some warranty-free opinions or links to credible sources on the subject.

Background: House is a circa 1901-1930 (who knows) frame and stucco house. I bought it with the bathroom already gutted and had a bathroom put in. I used t he same configuration as the original as I actually liked the layout. The toilet is over the porch, sink is slightly over the porch, shower is over the interior hallway.


  • Jamie Hall
    Jamie Hall Member Posts: 22,892
    PEX isn't usually damaged permanently by freezing... usually. Chances are that if it doesn't leak having been thawed, it isn't going to. However -- do make sure that it has all the insulation possible between it and the outside wall, and if possible the pipes in contact with the inside wall (which is warmer). One of the other places we care for has a similar arrangement... we always leave a trickle going into the sink in this weather.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,229
    From HH: https://heatinghelp.com/systems-help-center/how-many-times-can-pex-freeze-before-bursting/ Jay Burch did study this for NREL and his report is mentioned in the above link. You likely have nothing to worry about, though I would isolate the PEX from the outdoors any way possible, as Jamie Hall suggested.

    Yours, Larry
  • Kahooli
    Kahooli Member Posts: 112
    Thanks guys, I had missed that article.