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!