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Community and Q&A

Open cell foam details in exposed floors

loveoldbrokenstuff | Posted in General Questions on

Hi folks. I’m an estimator for an  insulation contractor in Ottawa, Canada (climate zone COLD!!!) and have been seeing quite a few clients complaining of uncomfortably cold rooms/floors in fairly recent (less than 5 years) builds.  
in both cases the floors overhang the porch, have a heat run in them, and are filled from below with 1/2 pound foam. The installations don’t look great—kinda like someone cut the top off a can of great stuff and threw it in there but I don’t see any major voids. The heat runs are probably too close to the bottoms leaving only a few inches for foam, but should that make the floor itself cold?
my best guess is there are air leaks and we have to tear it all out and redo the installation with closed cell foam, or try to build a heated drop, though there probably won’t be room. 

Any thoughts welcome! I don’t want to pull out a bunch of foam at great effort, put in more and find little improvement. Pictures include one from a client before their house was finished.  

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  1. GBA Editor
    Brian Pontolilo | | #1

    Hi Blake.

    I'll leave the question of fixing what you have there to others. If you end up tearing out the existing insulation, here are some articles you may consider reading about how to detail these floors well:
    Insulating a Wood-Framed Floor Assembly
    How to Insulate a Cold Floor

  2. Jon_R | | #2

    What is the temperature of the cold floor (over joists and between them) and how does it compare to the floor temperature two feet in from the overhang? Thermal loss will change right at the edge - air leaks and convection from windows will be less distinct.

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