Doubling insulation
#2
Group Moderator
#3
Member
I'm guessing your question is about the amount of insulation that can be placed in a space 8 1/4" high. If so, the answer is 8 1/4". Placing more insulation isn't only worthless but compressing insulation reduces it's effectiveness.
Not all insulation is equivalent, though. You may be able to increase the insulation's benefit by using a type of insulation with a higher R-value. For example, foam insulation can be superior to other insulation materials.
Not all insulation is equivalent, though. You may be able to increase the insulation's benefit by using a type of insulation with a higher R-value. For example, foam insulation can be superior to other insulation materials.