how much difference in price and quality between R19 and R20 per square feet ?? & |3 |' Y, W# S/ _5 d# B9 | ?0 ` H( F; P1 u+ t8 x; C
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who can explain why use R30 for attic. 4 V' ]- A- I K. l% A
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Thanks
1#KochFord% e! Y6 k2 H+ O; R
The higher R value, The better insulation performance.: e0 t* D1 k% @0 j q3 ]
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.& M$ ^8 c) w' c8 @9 ^
Hope my answer helps.