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.
It is well worth the effort to rough out the wall system to be square and level so the roof framing is simple.
If you notice that there is a visible dip in your roof chances are you have a problem with one or several rafters and you may soon be facing more issues like water leaks bowed out walls or your roof caving in on you.
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.
While it isn t that difficult to build rafters the wall system supporting the roof must be level and square.
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.
If needed shim trusses or rafters to level the nailing surface and install blocking to straighten any warped or bowed top chords of trusses or rafters.