how much difference in price and quality between R19 and R20 per square feet ?? A3 O+ S: m i( T
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who can explain why use R30 for attic. 5 O+ O) L" j* @4 ^! H% |' d3 x! l0 u0 k) c9 j. H2 |
Thanks
1#KochFord ( |9 \, w, `/ F c4 |The higher R value, The better insulation performance./ _. j6 j+ H E4 r0 x2 v) P
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. . j9 s1 s, S+ OHope my answer helps.