I just built a new garage with a heated floor and I'm just getting around to deciding how to insulate it. I've been thinking about spray foaming the side walls and putting fiberglass insulation in the ceiling. I got 2 bids to spray foam the walls, and both guys mentioned a "hot roof" option. My understanding of the 'hot roof" is to spray foam the entire garage incuding under the roof. This requires no venting and just seems a little odd to me. Anyone have some feedback?
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Hot Roof System?
- Thread starter hockey99
- Start date
ishiboo
Well-known member
I just built a new garage with a heated floor and I'm just getting around to deciding how to insulate it. I've been thinking about spray foaming the side walls and putting fiberglass insulation in the ceiling. I got 2 bids to spray foam the walls, and both guys mentioned a "hot roof" option. My understanding of the 'hot roof" is to spray foam the entire garage incuding under the roof. This requires no venting and just seems a little odd to me. Anyone have some feedback?
I researched this as I was going to spray foam and do a hot deck in my second floor home renovation.
You'll hear varying theories about shingle life/deck life/thermal efficiency/etc., but overall I think the rule of thumb should be if going with a hot deck improves the space, go for it. If you don't need it, don't do it and go with a conventional vented setup.
My cousin is in charge of our building inspection division, a former HVAC inspector and knows a lot about insulation - he said go for it if you like the space, the difference in performance is negligable. For more insulated space you do pay a lot to get the same or similar R-value in a small cavity though versus having a blown-in attic with potentially 3-4' of insulation.
czimmer1
Active member
We did a hot deck install on our garage with a bonus room above it and would never do anything different. we did fiberglass in our bonus room in the house and it isnt even close to the same. the hot deck keeps our bonus room the exact temp as the garage below.