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Ideas on insulating under retro-fit quik-trak

Rocky Member Posts: 121
Have had several homeowners call me regarding retrofitting a floor with Quik-Trak style pre-made panels. They have seen them at home shows, TV, etc. My question is, if they want to lay this down over slab on or below grade, and there wasn't insulation under this slab to begin with, how do we keep the heat from going down into the slab and to the ground? Insul-tarp is a little too thick and squishy to lay the panels on, isn't it? Along these same lines, I have come across some folks who have installed their subfloor on 2X6's laid on a slab. The 3/4" deck is already on and now they've heard about Quik-Trak and want a radiant floor. Short of pulling up the plywood deck and insulating the joist bays (which would be a real bugger since the walls are already framed in), again, how do we keep the heat from going down into the joists, into the slab and into the ground? What are you guys doing and using? Just looking for a little feedback as I have been asked to do the heating on several of these jobs and have yet to give them a bid.

Happy Heating,


  • for the joist bays

    you could drill and use blown in insulation. if your wiring is o.k. bob
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  • Phil_8
    Phil_8 Member Posts: 39

    Good question. As Hot Rod has pointed out, he had not yet found a foam insulation board that is termite proof. (Are there any termites in Alaska)? But it is something that we folks down south need to consider. If anyone knows of a termite resistant foam board product, we would appreciate the information. In the past HR has pointed us to Beaver Plastics, a Canadian company.
  • hot_rod
    hot_rod Member Posts: 15,033
    Expanding foam

    might work for that exisiting floor application. It comes in different expansion rates now a days. So you don't raise the plywood!! :)

    I haven't found any thin insulations to use under the "on top" products. Junkers and a few other hardwood companies have a thin foam underlayment. Not much R value, in an 1/8" thickness however.

    Personally I feel you need a minimun of 1" between the slab and panels. The more the merrier! That 1" often pushes the project beyond the do-able when floor heights are important, however.

    Sometimes better to walk away from a radiant system if adequate R cannot be included to make it work properly and economically. No one wants to be saddled with an expensive to install and operate "underperformer" for the rest of their life. Trust me on that one :)

    hot rod
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • kevin_5
    kevin_5 Member Posts: 308

    I just did a room in my basement with homemade quik trak and double groove heat emission plates on top. I used Low-E brand "slab shield" foam/foil/foam about 1/2" thick,
    (I have no data on compression, but I feel it is adequate)with 1/2 OSB floating on top in full size sheets, (unattached to the floor) then the 7" strips (homemade quik trak)
    of OSB screwed to that to make it essentially one big piece of OSB.
    I figured if the floating laminate floor works, why couldn't my radiant float as well. It works well, and is the quickest responder in the house. We have staple up, inslab, radiant ceiling, and now homemade quik trak over concrete, sort of a little radiant test lab.
    I have also removed floorboards and did the blow in insul. on a 2nd story job. I would recommend it. Kevin

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  • Phil_8
    Phil_8 Member Posts: 39
    ? for Kevin

    Did you use laminate flooring over your home made OSB quick track or something else?
  • Rocky
    Rocky Member Posts: 121
    Thanks for the replies..

    I hadn't considered cutting the deck and blowing in insulation. That is a pretty good idea. That's why I come to the Wall. Thanks to all for their input.
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