In his exclusive interview with House Digest, contractor Kevin Keen explained how to insulate a garage ceiling with rigid foam board, mineral wool, spray foam, and blown-in insulation.

This is as true for insulation board as it is for the ubiquitous expanded ... hot flexible wand through rigid foam just right, without making burn marks, is pretty frustrating.

The drawing shows how to install a wide board for the eaves to accomplish ... The other issue is insulation levels. Two inches of rigid foam has an R value of only about 10, which is not enough ...