how much difference in price and quality between R19 and R20 per square feet ?? 3 o$ l6 j5 H. G! g$ P( m8 r2 k3 k1 |* h2 q" I
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who can explain why use R30 for attic. 8 M9 [5 |. t# X6 w& o
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Thanks
1#KochFord; w4 s: H1 k( {* G9 S( Y
The higher R value, The better insulation performance.; D( d# ]& P- B! [# ^4 i
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. ' U# z- e: t+ h; \Hope my answer helps.