Insulation on Rafters Re: the Lifetime of Roof

Below is what our roofing expert John Stout from Go Roof Tune Up had to say in response to the above question:

 

Extreme Heat and improper ventilation will cause premature deterioration of roof shingles. Having a Batt Insulation layer between rafters should not have a negative effect on the life of the shingles. Attic temperatures are an important part of the equation in calculating shingle life.

 

I think insulation between rafters would be without problems as long as it did not restrict the normal ventilation and would not create hot spots at the roof sheathing.