I am going to have cathedral rafters that are 2' deep on a 6.5/12 pitch over a great room. The rafters will get covered with a sheathing board and then 2x4 purlins on top of that. The metal will then be attached to the metal Purlins.
For insulation I was going to pray closed cell foam to the underside of the sheathing. At least enough to make a vaper barrier. Then either open cell or fiberglass or batts to make up the R-value needed (R-49) in SE Indiana. If this is a bad idea please let me know.
What about the metal roofing sweating.. Should I put tar paper on the sheathing board or a membrane under the metal to prevent it from routing out the sheathing board?
For insulation I was going to pray closed cell foam to the underside of the sheathing. At least enough to make a vaper barrier. Then either open cell or fiberglass or batts to make up the R-value needed (R-49) in SE Indiana. If this is a bad idea please let me know.
What about the metal roofing sweating.. Should I put tar paper on the sheathing board or a membrane under the metal to prevent it from routing out the sheathing board?
Comment