Hot roof cathedral ceiling insulation
Hope I’ve put this in the right category. I’ve read through the information on here about insulation options for my non-vented Cathedral ceiling and am none the wiser…
I live outside Los Angeles in zone 3. New
master bedroom cathedral ceiling we are currently building has been designed to be a hot roof – no ventilation, and uses 2×8 beams. Roof sheathing is OSB with reflective coating facing into the roof cavity.
Best I can tell from my reading, I need to use either spray foam or rigid board. I can’t tell if I then need to fill the extra with batts or not to fill up the space.
We need R-30 in this cavity per our Title 24 report.
The structural engineer designed the ceiling with a parallam so the framer is putting a small cross base a few inches below the parallam so that we can hang a light. This will give space to run electrical wires. I assume that we’ll need to fill this space with insulation before drywalling?
We we’re planning to put 4 can lights in the angled portion of the ceiling in order to get the lighting we need in the space, but I’ve only come across something today (after several weeks of research) that can lights in a “hot roof” is not the thing to do.
Can lights are in, wires run, but they aren’t live yet.
So confused… so much of what I read is for areas farther north that get ice in the winter.
Can anyone point me in the right direction?
GBA Detail Library
A collection of one thousand construction details organized by climate and house part