Roof construction for a low-slope roof?
Our house is being built near the boundary of zone 4 and 5 in Illinois with a 1:12 pitch metal roof. I’ve done a lot of research on low-slope roofs because our builder does not have a lot of experience with flat roofs. After reading a couple of Martin’s articles and his advice on a previous question, we’re thinking we would like to create an unvented roof assembly (see sketch). We’re thinking of filling the rafters with enough dense-packed cellulose to get the total roof assembly to R50. I also included our elevations. Since this is all new to us, my wife and I would greatly appreciate a little help with a few questions we have.
Does this diagram look like a good approach?
Are the rafters built using roof trusses?
Any details that I should pass along to our builder about the roof trusses?
Should the ceiling be flat or should it follow the roofline? We’re open to either option.
Thanks in advance!
GBA Detail Library
A collection of one thousand construction details organized by climate and house part