To add more effective insulation on the roof and to eliminate thermal bridging we have add 2 layers of 1.5 inches of polyisocyanurate foam insulation. The first layer was applied as a continuous layer on top the plywood and the felt. Then the second layer was installed between 2 x 4 nailers with no overlap of seams below. I'll get Carlton to take some pictures tomorrow.
I am trying to figure out how to seal these edges of foam on the roof. I meant for the Carlton, Chris, and Myron crew to do that as they went along, but I did not specifically tell them to do that.
I have posted a question on Green Building Advisor for help with this matter.