I am insulating the ceiling in my sunroom. The rafters are 2x6 so I only have 5.5" of space for insulation, I planned on getting an R23 for the 2x6 and I also planned on putting a 1" Rigid foam under that to try and get to an R value of 30.
My question is with the many different types of foam insulation, which one should I choose? I found one at Lowes and one at Home Depot but i am not sure which is better, both have an R value of 6.5 but i am not sure which is better for an interior ceiling?
Any help or suggestions would be greatly appreciated, thanks!
Home Depot Insulation