1#KochFord ' m/ ~, L `- x9 K& i, vThe higher R value, The better insulation performance. " g8 ?: ]2 I# l* d4 M7 kIn winter, the hot air always floats up due to thermal buoyancy, so R value for the roof is normally higher than that for exterior wall. 9 O. U& U# T0 o1 w) s# a8 y& _Hope my answer helps.