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Open web truss and plate insulation idea

hot_rod
hot_rod Member Posts: 22,791
a plate job in a new home with open trusses. I'm thinking of prefabing some 2" foam with ThermoFin and 1/2" copper.

Long grabber screws with fender washers would fasten the assembly to the floor.

I have a friend with a large CNC router table that can handle 80 sheets an hour. He is willing to try routering some foam for me.

Any thoughts?

hot rod
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream

Comments

  • tombig
    tombig Member Posts: 291


    The install procedure is a little unclear. Are you going to install these in the joist bays under the subfloor? Are you going to sweat/swedge each pex/cu. conn. at each bay? Prependicular to the trusses maybe? A nice tight fit of 1 1/2" insul. seems great for a staple up. Have your guy router some panels with a wide groove that will over(under)lay your tube and plates,allowing for variances in plate/tube install. Install insul. after tube. Moisture could build up in an "insulation sandwich" during the off season.

    Tombig


  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
    Looks VERY nice

    Certainly MUCH easier and more effective than my clumsy way...

    If the CNC works, the cost should certainly be worth the aggravation of doing it by hand on a large scale.

    Are you using rigid copper for the runs with pre-made end bends? Kind of looks like that's your intent.

    Would HIGHLY suggest that you make a spacing jig or two(piece of hardwood with accurate notches to accommodate the fin Ds.) The jig should "start" at a truss plate edge and accommodate however many runs are in the bay. That should pretty well guarantee you keep your spacing nice and parallel. 1/4" tolerance at the sides? 2" foam is rather difficult to "force".

    Lots of wood/heavy floor coverings above? Designed for supply temp below condensing all the time?
  • Steve Bergerson
    Steve Bergerson Member Posts: 38
    Fingernails on a Blackboard...

    If you've ever driven a service van with a piece of equipment packed with foam, you know the sound it makes as you drive down the road. A high pitched squeak.. drives you nuts!

    As your pipes expand in this install method, you might have some interesting noises.... just a thought.
  • I've seen...

    these perforated squares with super sticky adhesive compound on them and a sharpened point 6" steel pin about the gauge of a knitting needle. You stick those to the sub floor, then stab R-19 fiberglass insulation onto them, then stab a self locking thin gauge fender washer onto the pins.

    Not sure how the sticky would hold up to the heat tho... Maybe you could screw the pins with sheet metal screws.

    ME


  • I have two thoughts:

    1. Cool idea, i just wonder about the expansion noise noted as a possibility in another post.. might be best to rout those grooves a little bigger

    and

    2. Why copper?
This discussion has been closed.