how much difference in price and quality between R19 and R20 per square feet ?? . I" @# {0 Z5 D s0 y# Q) j3 n2 O! Q- S. _
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who can explain why use R30 for attic. 9 S4 C ~& F E! w+ M+ ^# `5 e6 l( P) A6 C- Y$ [
Thanks
1#KochFord! A+ p, E# M# K
The higher R value, The better insulation performance. u( i! a: a+ ^$ h
In 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. 2 |% w+ e3 T7 z* X3 S5 O2 wHope my answer helps.