Florida home roof insulation and wall to roof connection details recommendation
High performance building newbie here. I’m planning new construction for my home in central Florida (climate zone 2) and need recommendations.
My roof is planned to be a low sloped (3/12 pitch), mono-sloped design. There’s no attic space inside. What would you recommend on an assembly like this, in my area, for high performance/pretty good design?
For the wall to roof connection, seems like high performance builders are cutting roof members at the wall to have a continuous layer of exterior insulation and air sealing. Anyone have experience in what’s possible for bolt on rafters in light of Florida wind codes? If I can’t bolt on rafters, how would you air seal the notoriously (so I’ve heard) hard to air seal wall to roof connection?
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Replies
Stephan,
GBA posters often recommend installing rigid foam on the exterior. I think that would be fairly easily to do on a shed roof. Exterior rigid also works well on walls--although it's not as big a deal in your climate.
Here is one article on insulating low-slope roofs (https://www.greenbuildingadvisor.com/article/insulating-low-slope-residential-roofs). Also check out the sidebar.
As for bolt-on rafters, you can find a video or two on the Home Performance Youtube channel. My recollection was the owner decided "never again" after doing that on his personal home.
With a mono-slope roof you are probably looking at I-joists or trusses for the roof structure.
The easiest with those is to go with a vented design with loose fill insulation. This would put your air barrier at the ceiling which is pretty straight forward to tie together with the sheathing air barrier. No need to worry about any bolt on rafters tails.