We started on the roof insulation this weekend. We are using a 3" thick foam board called Iso board. It's similar to the Dow blue board that you may have seen in Lowe's or Home Depot but it has a 18.5 R- value where the Dow board is R-15 and it was only about $1.25 a sheet more. That's a 4' x 8' sheet. It has about 45% recycled content too, so I was happy about that. It is normally used for commercial structures but is great for this application. The gable end of the house (where there is attic) will also have traditional bat insulation so that end will be really well insulated.
We ran two 2x4's all around the perimeter of the roof and then started laying down one run of Iso board all the way across the roof and then sandwiched that with 2x4's. Then just keep repeating until you reach the top. The only thing about the Iso board is it has alot of fiberglass in the outer paper coating so I was SO itchy at the end of the day.
After we ran all the insulation we went over that with this high tech new roofing felt stuff I got for free off of a job. It's not really felt; it's more like a vinyl type stuff. It's great to work with though. It lays down very nice. We put this down because we are going to have a metal roof and you usually get some condensation under a metal deck and this material will protect the framing and insulation from getting damp. Plus, it didn't cost me anything so, what the heck!
In putting all this down it meant we had to take up our toe-boards from the roof and therefore nothing to catch on if you start sliding. The roof is not really steep but Allen was afraid this material might be slick and he knows how clumsy I am, so I got to wear that wonderfully attractive harness.
This is just a close up of the "felt" we used. Cool stuff and it's treated somehow to be non- skidding to walk on. It also comes in 4' wide rolls whereas traditional roofing felt comes in 3' wide rolls. I thought it was funny how they put little bullseyes everywhere you are supposed to nail it too. And no, we didn't nail it everywhere they said as you can probably see.