Mineral wool friction fits between rafters providing an optimum seal and preventing gaps associated with rigid foam boards which can otherwise lead to unwanted heat loss.
How to level roof rafters.
If your rafters are still sagging a bit and it is causing your roof to dish out a little in the center of the roof sides add a 2x4 that goes all the way across the rafters in the center of the length of the rafters.
If one support is as little as 1 4 inch lower or higher than the one next to it you might end up with an uneven roof.
Download our solutions guide download our pitched roofs rafter level pdf.
Sagging rafters can lead to serious problems with the entire roofing system.
Use your string line to determine how much the roof need to go up.
In order to build rafters you need to know the roof pitch and the roof span overall width of roof.
It is well worth the effort to rough out the wall system to be square and level so the roof framing is simple.