Masonry Magazine June 1975 Page. 16
TABLE 1ª
Heat Transmission Coefficients of Building Materials
| Materials Description | Conductivity or Conductance | Resistance(R) |
|---|---|---|
| | (k) | (C) | Per Inch Thickness (1/k) | For Thickness Listed (I/C) |
| Air Surfaces | | | | |
| Inside still air | 1.47 | | 0.68 | |
| Outside-15 mph wind, winter | 6.00 | | 0.17 | |
| 7.5 mph wind, summer | 4.00 | | 0.25 | |
| Air Space | | | | |
| ¾ in. to 4 in., winter | 1.03 | | 0.97 | |
| ¾ in. to 4 in., summer | 1.16 | | 0.86 | |
| Masonry Units | | | | |
| Face brick-130-lb density | 9.00 | | 0.11 | |
| Common brick-120-lb density | 5.00 | | 0.20 | |
| Hollow brick-128-1b density | | | | |
| 4 in. (62.9% solid) | 1.36 | | 0.74 | |
| 6 in. (67.3% solid) | 1.07 | | 0.93 | |
| 8 in. (61.2% solid) | 0.94 | | 1.06 | |
| 10 in. (60.9% solid) | 0.83 | | 1.20 | |
| Hollow brick, vermiculite fill-128-lb density | 0.91 | | 1.10 | |
| 4 in. (62.9% solid) | 0.66 | | 1.52 | |
| 6 in. (67.3% solid) | 0.52 | | 1.92 | |
| 8 in. (61.2% solid) | 0.42 | | 2.38 | |
| 10 in. (60.9% solid) | 0.71 | | 1.40 | |
| Lightweight concrete block-100-lb density | 0.65 | | 1.53 | |
| 4 in. | 0.57 | | 1.75 | |
| 6 in. | 0.51 | | 1.97 | |
| 8 in. | 0.47 | | 2.14 | |
| 10 in. | 0.43 | | 2.33 | |
| 12 in. | 0.27 | | 3.72 | |
| Lightweight concrete block, vermiculite fill-100-lb density | 0.21 | | 4.85 | |
| 4 in. | 0.17 | | 5.92 | |
| 6 in. | 0.15 | | 6.80 | |
| 8 in. | | | | |
| 10 in. | | | | |
| 12 in | | | | |
| Building Board | | 3.10 | | 0.32 |
| %-in. Drywall (gypsum) | | 2.25 | | 0.45 |
| ½-in. Drywall (gypsum) | | 0.80 | | 1.25 |
| Plywood | | 0.76 | | 1.32 |
| ½-in. Fiberboard sheathing | | | | |
| Siding | | 1.49 | | 0.67 |
| -in. Hardboard | | 1.23 | | 0.81 |
| ½-in. by 8-in. Wood bevel | | 1.61 | | 0.61 |
| Aluminum or steel over sheathing" | | | | Continued on next page |
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