how much difference in price and quality between R19 and R20 per square feet ?? 2 K) b4 i) U4 G( l( Y7 k : e% d1 y. T# y0 O2 f( M. N, p1 t7 Q& W2 D) i. n
who can explain why use R30 for attic. 8 [) ~& P" V6 r* G0 |" E
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Thanks
1#KochFord / z" S; G+ Y' B4 Y' nThe higher R value, The better insulation performance.5 h6 n' K! P/ v
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. 1 w- E2 a f% M' CHope my answer helps.