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Insulating open trusses.

kcopp Member Posts: 3,752
What doing a staple up radiant floor w/ plates and the floor has to be insulated.
How does one go about doing a good job when using batt type insulation when the trusses are open on the sides? What practices have you seen done that work?


  • Gordy
    Gordy Member Posts: 9,514
    edited December 2017
    What rvalue batts? What are truss centers? Double top cord plate?
  • kcopp
    kcopp Member Posts: 3,752
    From the pix it looks like 24 oc. single top plates. open webs. prob do r-21
  • Gordy
    Gordy Member Posts: 9,514
    Well I can think of a couple ways good, better, and best.. easy, hard, and harder. Depends how much mechanical is up in that region.

    Spray foam

    1x8 nailed to side of truss to hold insulation batt, and isolate the bay. Cut as needed to length to miss mechanicals.

    Run rolls of tie wire pulled tight perpendicular to trusses fastened at cord locations to desired height to hold batts in position. Probably 2’ oc. May be the easiest.

    If it were 16” OC I would have said 24” batts cut around cords and stapled to cords.

  • Zman
    Zman Member Posts: 6,636
    You may be able to attach insulation skewers to the bottom of decking then use the big square washers to hold it up.
    I would consult the insulators.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Gordy
    Gordy Member Posts: 9,514
    Could just say I’m throwing ceiling radiant in for free :D ..........kidding.
    kcoppCanuckerMark Eatherton
  • Paul48
    Paul48 Member Posts: 4,470
    Why batts?
  • kcopp
    kcopp Member Posts: 3,752
    Paul48 said:

    Why batts?

    Batts allow you to get back into the area for future changes or repairs or running a new wire...
    Spray foam just seems so final.
    Just wondering what others have done to keep the heat in and directed up....
  • Paul Pollets
    Paul Pollets Member Posts: 3,399
    Batts are the way to go
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,837
    Gordy said:

    Could just say I’m throwing ceiling radiant in for free :D ..........kidding.

    Better yet, bi-directional radiant heating :smiley:


    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
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