how much difference in price and quality between R19 and R20 per square feet ?? " ]) p8 S& R- @3 C! @' ?! ^3 C4 f# E( j# ~3 x, d, u! y
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who can explain why use R30 for attic. # L4 [3 f( [/ }: ~- D 2 v+ Q( C" d8 y" [) oThanks
1#KochFord 0 s8 ]# A& i- {The higher R value, The better insulation performance. 6 Q' I3 T& M$ w, rIn 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. 5 d0 A) h7 W4 X5 B ^Hope my answer helps.