ASHRAE-90.1-2022- - Page 235
Extracted Content
Table A2.4.2 Single-Rafter Roofs
| Climate Zone | Minimum Insulation R-Value or Maximum Assembly U-Factor | Col3 | Col4 |
|---|---|---|---|
| Climate Zone | Wood Rafter Depth,****d (Actual) | Wood Rafter Depth,****d (Actual) | Wood Rafter Depth,****d (Actual) |
| Climate Zone | d 8 in. | 8 < d** 10 in.** | 10 < d** 12 in.** |
| 0 to 7 | R-19/U-0.055 | R-30/U-0.036 | R-38/U-0.028 |
| 8 | R-21/U-0.052 | R-30/U-0.036 | R-38/U-0.028 |
Table A2.4.3 Assembly U-Factors for Attic Roofs with Wood Joists
| Rated R-Value of Insulation Alone | Overall U-Factor for Entire Assembly | Col3 | Col4 | Col5 |
|---|---|---|---|---|
| Wood-Framed Attic, Standard Framing | Wood-Framed Attic, Standard Framing | Wood-Framed Attic, Standard Framing | Wood-Framed Attic, Standard Framing | Wood-Framed Attic, Standard Framing |
| None | U-0.613 | U-0.613 | U-0.613 | U-0.613 |
| R-11 | U-0.091 | U-0.091 | U-0.091 | U-0.091 |
| R-13 | U-0.081 | U-0.081 | U-0.081 | U-0.081 |
| R-19 | U-0.053 | U-0.053 | U-0.053 | U-0.053 |
| R-30 | U-0.034 | U-0.034 | U-0.034 | U-0.034 |
| R-38 | U-0.027 | U-0.027 | U-0.027 | U-0.027 |
| R-49 | U-0.021 | U-0.021 | U-0.021 | U-0.021 |
| R-60 | U-0.017 | U-0.017 | U-0.017 | U-0.017 |
| R-71 | U-0.015 | U-0.015 | U-0.015 | U-0.015 |
| R-82 | U-0.013 | U-0.013 | U-0.013 | U-0.013 |
| R-93 | U-0.011 | U-0.011 | U-0.011 | U-0.011 |
| R-104 | U-0.010 | U-0.010 | U-0.010 | U-0.010 |
| R-115 | U-0.009 | U-0.009 | U-0.009 | U-0.009 |
| R-126 | U-0.008 | U-0.008 | U-0.008 | U-0.008 |
| Wood-Framed Attic, Advanced Framing | Wood-Framed Attic, Advanced Framing | Wood-Framed Attic, Advanced Framing | Wood-Framed Attic, Advanced Framing | Wood-Framed Attic, Advanced Framing |
| None | U-0.613 | U-0.613 | U-0.613 | U-0.613 |
| R-11 | U-0.088 | U-0.088 | U-0.088 | U-0.088 |
| R-13 | U-0.078 | U-0.078 | U-0.078 | U-0.078 |
| R-19 | U-0.051 | U-0.051 | U-0.051 | U-0.051 |
| R-30 | U-0.032 | U-0.032 | U-0.032 | U-0.032 |
| R-38 | U-0.026 | U-0.026 | U-0.026 | U-0.026 |
| R-49 | U-0.020 | U-0.020 | U-0.020 | U-0.020 |
| R-60 | U-0.016 | U-0.016 | U-0.016 | U-0.016 |
| R-71 | U-0.014 | U-0.014 | U-0.014 | U-0.014 |
| R-82 | U-0.012 | U-0.012 | U-0.012 | U-0.012 |
| R-93 | U-0.011 | U-0.011 | U-0.011 | U-0.011 |
| R-104 | U-0.010 | U-0.010 | U-0.010 | U-0.010 |
| R-115 | U-0.009 | U-0.009 | U-0.009 | U-0.009 |
| R-126 | U-0.008 | U-0.008 | U-0.008 | U-0.008 |
| Wood Joists, Single-Rafter Roof | Wood Joists, Single-Rafter Roof | Wood Joists, Single-Rafter Roof | Wood Joists, Single-Rafter Roof | Wood Joists, Single-Rafter Roof |
| Cavity Insulation R-Value | Overall U-Factor for Assembly of Base Roof Plus Continuous Insulation (Uninterrupted by Framing) | Overall U-Factor for Assembly of Base Roof Plus Continuous Insulation (Uninterrupted by Framing) | Overall U-Factor for Assembly of Base Roof Plus Continuous Insulation (Uninterrupted by Framing) | Overall U-Factor for Assembly of Base Roof Plus Continuous Insulation (Uninterrupted by Framing) |
| Cavity Insulation R-Value | Rated R-Value of Continuous Insulation | Rated R-Value of Continuous Insulation | Rated R-Value of Continuous Insulation | Rated R-Value of Continuous Insulation |
| Cavity Insulation R-Value | None | R-5 | R-10 | R-15 |
| None | U-0.417 | U-0.135 | U-0.081 | U-0.057 |
| R-11 | U-0.088 | U-0.061 | U-0.047 | U-0.038 |
| R-13 | U-0.078 | U-0.056 | U-0.044 | U-0.036 |
| R-15 | U-0.071 | U-0.052 | U-0.041 | U-0.034 |
| R-19 | U-0.055 | U-0.043 | U-0.035 | U-0.030 |
| R-21 | U-0.052 | U-0.041 | U-0.034 | U-0.029 |
| R-25 | U-0.042 | U-0.035 | U-0.030 | U-0.026 |
| R-30 | U-0.036 | U-0.030 | U-0.026 | U-0.023 |
| R-38 | U-0.029 | U-0.025 | U-0.022 | U-0.020 |
ANSI/ASHRAE/IES Standard 90.1-2022 (I-P) 233