Building a Subfloor on Top of Foam Over Slab
Hello, I have read so much on this forum and learned a ton. I am renovating my house (2 hours north of toronto, ontario). I am converting my old slab on grade (uninsulated) garage to a 4 season living space. I am going to be heating the space by attaching it to my existing HVAC system, and so I need to have heat runs in the floor. I would need about 5-6″ of space for the heat runs.
I want to know if I can lay 35PSI foam on top of the concrete and THEN build a traditional style subfloor with 2×6’s on edge so that I have space for my HVAC runs in the floor? (I have tons of ceiling height to work with so the floor being thicker is not an issue). ie have the 2×6 on edge directly on the foam.
The other way I have seen this done is by having 2×2 sleepers on the concrete and then I can insulate between them with the foam – this brings up a thermal bridge from my cold uninsulated concrete slab – but if it has to be done this way then I will.
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