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Spray-in Foam Insulation

mph
mph Member Posts: 77
We're starting a job with Thermofin plates stapled-up in the joist bays and 3/8" Rehau tubing. The GC is going to spray in Poly-iconene (sp) foam insulation. The foam will adhere directly to the bottom of the sub-floor, as well as the bottom of the plates. Assuming this isn't a problem with the Pex (I'll check with the mfg), what do you think about covering the bottom half of the plates with this foam? How much loss should I expect in heat transfer?

Anybody had any experience with this?

Jeff

Comments

  • hr
    hr Member Posts: 6,106
    Should work

    I did that exact install this fall. ThermoFim with isoneyne sprayed against the entire assembly.

    We went with 4". Make sure your supply temperatures work with the Isoneyne. Generally plates run below 130°.

    The only issue I worry about is finding a leak, shaould the flooring guy nail me :)

    This floor has been running several months now and has seen some single digit days. Works great. A much better insulation package than batts for this job, as it was all open web truss. Real hard to keep batts in those joists.

    hot rod

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  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
    Loss in heat transfer?

    It won't be a loss--it will be a gain as the insulation will be extremely effective at blocking both radiation and convection from the underside of the plates allowing it to conduct to the floor as greatly as possible.

    Remember: with heavy plates you want to insulate DIRECTLY against them to STOP the convection/radiation on the underside from robbing BTUs from the conduction up top.
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