R-Value Range |
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Type |
Walls |
Interior Walls |
Floors |
Bsmt / Crawl Spaces |
Attics |
2X4 |
2X6 |
Fiber Glass Batt |
R-13 to R-15 |
R-19 to R-23 |
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Fiber Glass Blow-in |
R-13 to R-16 |
R-20 to R-25 |
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Mineral Wool Batt |
R-13 to R-15 |
R-22 to R-23 |
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Mineral Wool Blow-in |
R-14.5 |
R-23 |
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Cellulose * |
R-12 to R-13 |
R-19 to R-20 |
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Spray Foam Open Cell** |
R-12 to R-13 |
R-19 to R-20 |
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Spray Foam Closed Cell** |
R-19 to R-22 |
R-32 to R-35 |
* Cellulose R-Values can be overstated due to potential settling over time.
** Spray foam R-Values assume full cavity installations, but full cavity installations with spray foam are difficult to achieve.