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Standard Oxygen Barrier pex or Pex-Al-Pex for staple up radiant heat?

grant_andrew Member Posts: 22
edited November 2019 in THE MAIN WALL
I’ll be adding staple-up radiant heat to my ~120 sq. ft. kitchen in a few weeks, and I was wondering if anyone feels strongly about using regular oxygen barrier pex versus pex-al-pex for the job. I just re-piped my boiler’s old 1¼” and 2” cast iron to ½” PAP using a homerun manifold setup, and I found the PAP really easy to work with. However, I wasn’t snaking it through floor joists like I would be on this job.

It’s such a small job that the cost difference between the two will be minimal, so I’m really looking for any ease-of-installation or performance benefits for one or the other. Any thoughts are appreciated, thanks!


  • STEVEusaPA
    STEVEusaPA Member Posts: 6,378
    Oxygen barrier, and use aluminum transfer plates.
  • Solid_Fuel_Man
    Solid_Fuel_Man Member Posts: 2,645
    I like a PEX-A such as Wirsbo/Uponor or Mr.PEX etc. Or PERT, from Watts. All easy to work with.

    I'll second the extruded Aluminum transfer plates.
    Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
  • grant_andrew
    grant_andrew Member Posts: 22
    Great, thanks!

    Do you prefer the extruded plates because they're easier to install, or because they give better heat transfer than the sheet metal ones?
  • kenjohnson
    kenjohnson Member Posts: 82
    I used the thick extruded plates that the PEX pushes into. Everything I read said that they would give better heat transfer than the thinner plates that fit over the PEX. I also read that the extruded plates would reduce ticking and popping sounds during warm-up. My system works as designed, so I can't complain, and it is silent.

    Re: installation, it's a lot easier to put the PEX into the extruded plates, I think. I installed the extruded plates using 1" self-driving hex-head screws, so it was pretty easy to put them up.
  • HomerJSmith
    HomerJSmith Member Posts: 2,309
    I have used sheet metal transfer plates. I sprinkle on baby powder on the grooves before snapping over the pex. It stops ticking.

    Be sure and leave at least 2" of air space between the insulation and the underfloor. Insulate real good to minimize back loss.
  • grant_andrew
    grant_andrew Member Posts: 22
    Thanks for the feedback! Barrier pex it is!