Section A103.3.7—Concrete and masonry walls.
A103.3.7 Concrete and masonry walls.
A103.3.7.1 Concrete masonry walls. The nominal R-values in Table A103.3.7.1 may be used for purposes of calculating concrete masonry wall section U-factors in lieu of the ASHRAE isothermal planes calculation method as provided in Chapter 27 of the ASHRAE Fundamentals Handbook.
Table A103.3.7.1
Default U-factors for Concrete and Masonry Walls
8" Concrete masonry
| CORE TREATMENT |
| Partial Grout with Ungrouted Cores | |
| | Loose-fill insulated | |
Wall Description | Empty | Perlite | Vermiculite | Solid Grout |
Exposed Block, Both Sides | 0.40 | 0.23 | 0.24 | 0.43 |
R-5 Interior Insulation, Wood Furring | 0.14 | 0.11 | 0.12 | 0.15 |
R-6 Interior Insulation, Wood Furring | 0.14 | 0.11 | 0.11 | 0.14 |
R-10.5 Interior Insulation, Wood Furring | 0.11 | 0.09 | 0.09 | 0.11 |
R-8 Interior Insulation, Metal Clips | 0.11 | 0.09 | 0.09 | 0.11 |
R-6 Exterior Insulation | 0.12 | 0.10 | 0.10 | 0.12 |
R-10 Exterior Insulation | 0.08 | 0.07 | 0.07 | 0.08 |
R-9.5 Rigid Polystyrene Integral Insulation, Two Webbed Block | 0.11 | 0.09 | 0.09 | 0.12 |
12" Concrete masonry
| CORE TREATMENT |
| Partial Grout with Ungrouted Cores | |
| | Loose-fill insulated | |
Wall Description | Empty | Perlite | Vermiculite | Solid Grout |
Exposed Block, Both Sides | 0.35 | 0.17 | 0.18 | 0.33 |
R-5 Interior Insulation, Wood Furring | 0.14 | 0.10 | 0.10 | 0.13 |
R-6 Interior Insulation, Wood Furring | 0.13 | 0.09 | 0.10 | 0.13 |
R-10.5 Interior Insulation, Wood Furring | 0.11 | 0.08 | 0.08 | 0.10 |
R-8 Interior Insulation, Metal Clips | 0.10 | 0.08 | 0.08 | 0.09 |
R-6 Exterior Insulation | 0.11 | 0.09 | 0.09 | 0.11 |
R-10 Exterior Insulation | 0.08 | 0.06 | 0.06 | 0.08 |
R-9.5 Rigid Polystyrene Integral Insulation, Two Webbed Block | 0.11 | 0.08 | 0.09 | 0.12 |
8" Clay brick
| CORE TREATMENT |
| Partial Grout with Ungrouted Cores | |
| | Loose-fill insulated | |
Wall Description | Empty | Perlite | Vermiculite | Solid Grout |
Exposed Block, Both Sides | 0.50 | 0.31 | 0.32 | 0.56 |
R-5 Interior Insulation, Wood Furring | 0.15 | 0.13 | 0.13 | 0.16 |
R-6 Interior Insulation, Wood Furring | 0.15 | 0.12 | 0.12 | 0.15 |
R-10.5 Interior Insulation, Wood Furring | 0.12 | 0.10 | 0.10 | 0.12 |
R-8 Interior Insulation, Metal Clips | 0.11 | 0.10 | 0.10 | 0.11 |
R-6 Exterior Insulation | 0.12 | 0.11 | 0.11 | 0.13 |
R-10 Exterior Insulation | 0.08 | 0.08 | 0.08 | 0.09 |
6-Inch Concrete Poured
or Precast
| CORE TREATMENT |
| Partial Grout with Ungrouted Cores | |
| | Loose-fill insulated | |
Wall Description | Empty | Perlite | Vermiculite | Solid Grout |
Exposed Concrete, Both Sides | NA | NA | NA | 0.61 |
R-5 Interior Insulation, Wood Furring | NA | NA | NA | 0.16 |
R-6 Interior Insulation, Wood Furring | NA | NA | NA | 0.15 |
R-10.5 Interior Insulation, Wood Furring | NA | NA | NA | 0.12 |
R-8 Interior Insulation, Metal Clips | NA | NA | NA | 0.12 |
R-6 Exterior Insulation | NA | NA | NA | 0.13 |
R-10 Exterior Insulation | NA | NA | NA | 0.09 |
Notes:
1. Grouted cores at 40" x 48" on center vertically and horizontally in partial grouted walls.
2. Interior insulation values include 1/2" gypsum board on the inner surface.
3. Furring and stud spacing is 16" on center. Insulation is assumed to fill furring space and is not compressed.
4. Intermediate values may be interpolated using this table. Values not contained in this table may be computed using the procedures listed in the ASHRAE Fundamentals Handbook.
5. Concrete masonry unit (CMU) assembly U-values are based on local test data for Washington state CMU block material using the ASTM C-236-87 steady state thermal conductance test. Tests included an 8"x8"x16" CMU with all cells filled with vermiculite (1995) and 8"x8"x16" CMU with all cells filled with polymaster foam in place insulation (1996). Refer to ASHRAE Standard 90.1 for additional nationally recognized data on the thermal performance of CMU block walls.
Table A103.3.7.1(2)
Default U-Factors for Concrete and Masonry Wallsa, b, c, d
Framing Type and Depth | Rated R-value of Insulation Alone | Assembly U-factors for Solid Concrete Walls | Assembly U-factors for Concrete Block Walls: Solid Grouted | Assembly U-factors for Concrete Block Walls: Partially Grouted (Cores Uninsulated Except Where Specified) |
Base Wall only | | | |
No Framing | R-0 | U-0.740 | U-0.580 | U-0.480 |
| Ungrouted Cores Filled with Loose-Fill Insulation | N.A. | N.A. | U-0.350 |
Continuous Wood Framing | | | |
0.75 in. | R-3.0 | U-0.247 | U-0.226 | U-0.210 |
1.5 in. | R-6.0 | U-0.160 | U-0.151 | U-0.143 |
2.0 in. | R-10.0 | U-0.116 | U-0.111 | U-0.107 |
3.5 in. | R-11.0 | U-0.094 | U-0.091 | U-0.088 |
3.5 in. | R-13.0 | U-0.085 | U-0.083 | U-0.080 |
3.5 in. | R-15.0 | U-0.079 | U-0.077 | U-0.075 |
5.5 in. | R-19.0 | U-0.060 | U-0.059 | U-0.058 |
5.5 in. | R-21.0 | U-0.057 | U-0.055 | U-0.054 |
Continuous Metal Framing at 24 in. on center horizontally | | |
1.0 in. | R-0.0 | U-0.414 | U-0.359 | U-0.318 |
1.0 in. | R-3.8 | U-0.325 | U-0.290 | U-0.263 |
1.0 in. | R-5.0 | U-0.314 | U-0.281 | U-0.255 |
1.0 in. | R-6.5 | U-0.305 | U-0.274 | U-0.249 |
1.5 in. | R-11.0 | U-0.267 | U-0.243 | U-0.223 |
2.0 in. | R-7.6 | U-0.230 | U-0.212 | U-0.197 |
2.0 in. | R-10.0 | U-0.219 | U-0.202 | U-0.188 |
2.0 in. | R-13.0 | U-0.210 | U-0.195 | U-0.182 |
3.0 in. | R-11.4 | U-0.178 | U-0.167 | U-0.157 |
3.0 in. | R-15.0 | U-0.168 | U-0.158 | U-0.149 |
3.0 in. | R-19.0 | U-0.161 | U-0.152 | U-0.144 |
3.5 in. | R-11.0 | U-0.168 | U-0.158 | U-0.149 |
3.5 in. | R-13.0 | U-0.161 | U-0.152 | U-0.144 |
3.5 in. | R-15.0 | U-0.155 | U-0.147 | U-0.140 |
4.5 in. | R-17.1 | U-0.133 | U-0.126 | U-0.121 |
4.5 in. | R-22.5 | U-0.124 | U-0.119 | U-0.114 |
4.5 in. | R-25.2 | U-0.122 | U-0.116 | U-0.112 |
5.0 in. | R-19.0 | U-0.122 | U-0.117 | U-0.112 |
5.0 in. | R-25.0 | U-0.115 | U-0.110 | U-0.106 |
5.0 in. | R-28.0 | U-0.112 | U-0.107 | U-0.103 |
5.0 in. | R-32.0 | U-0.109 | U-0.105 | U-0.101 |
5.5 in. | R-19.0 | U-0.118 | U-0.113 | U-0.109 |
5.5 in. | R-20.9 | U-0.114 | U-0.109 | U-0.105 |
5.5 in. | R-21.0 | U-0.113 | U-0.109 | U-0.105 |
5.5 in. | R-27.5 | U-0.106 | U-0.102 | U-0.099 |
5.5 in. | R-30.8 | U-0.104 | U-0.100 | U-0.096 |
6.0 in. | R-22.8 | U-0.106 | U-0.102 | U-0.098 |
6.0 in. | R-30.0 | U-0.099 | U-0.095 | U-0.092 |
6.0 in. | R-33.6 | U-0.096 | U-0.093 | U-0.090 |
6.5 in. | R-24.7 | U-0.099 | U-0.096 | U-0.092 |
7.0 in. | R-26.6 | U-0.093 | U-0.090 | U-0.087 |
7.5 in. | R-28.5 | U-0.088 | U-0.085 | U-0.083 |
8.0 in. | R-30.4 | U-0.083 | U-0.081 | U-0.079 |
1 in. Metal Clips at 24 in. on center horizontally and 16 in. vertically (also, where allowed by Section C402.1.3, for assemblies with a ratio of metal penetration area/mass wall area of < 0.0004 or < 0.04% of the mass wall area) See ASHRAE Fundamentals for determination of U-factors for assemblies that include metal other than screws and nails. |
1.0 in. | R-3.8 | U-0.210 | U-0.195 | U-0.182 |
1.0 in. | R-5.0 | U-0.184 | U-0.172 | U-0.162 |
1.0 in. | R-5.6 | U-0.174 | U-0.163 | U-0.154 |
1.5 in. | R-5.7 | U-0.160 | U-0.151 | U-0.143 |
1.5 in. | R-7.5 | U-0.138 | U-0.131 | U-0.125 |
1.5 in. | R-8.4 | U-0.129 | U-0.123 | U-0.118 |
2.0 in. | R-7.6 | U-0.129 | U-0.123 | U-0.118 |
2.0 in. | R-10.0 | U-0.110 | U-0.106 | U-0.102 |
2.0 in. | R-11.2 | U-0.103 | U-0.099 | U-0.096 |
2.5 in. | R-9.5 | U-0.109 | U-0.104 | U-0.101 |
2.5 in. | R-12.5 | U-0.092 | U-0.089 | U-0.086 |
2.5 in. | R-14.0 | U-0.086 | U-0.083 | U-0.080 |
3.0 in. | R-11.4 | U-0.094 | U-0.090 | U-0.088 |
3.0 in. | R-15.0 | U-0.078 | U-0.076 | U-0.074 |
3.0 in. | R-16.8 | U-0.073 | U-0.071 | U-0.069 |
3.5 in. | R-13.3 | U-0.082 | U-0.080 | U-0.077 |
3.5 in. | R-17.5 | U-0.069 | U-0.067 | U-0.065 |
3.5 in. | R-19.6 | U-0.064 | U-0.062 | U-0.061 |
4.0 in. | R-15.2 | U-0.073 | U-0.071 | U-0.070 |
4.0 in. | R-20.0 | U-0.061 | U-0.060 | U-0.058 |
4.0 in. | R-22.4 | U-0.057 | U-0.056 | U-0.054 |
5.0 in. | R-28.0 | U-0.046 | U-0.046 | U-0.045 |
6.0 in. | R-33.6 | U-0.039 | U-0.039 | U-0.038 |
7.0 in. | R-39.2 | U-0.034 | U-0.034 | U-0.033 |
8.0 in. | R-44.8 | U-0.030 | U-0.030 | U-0.029 |
9.0 in. | R-50.4 | U-0.027 | U-0.027 | U-0.026 |
10 in. | R-56.0 | U-0.024 | U-0.024 | U-0.024 |
11 in. | R-61.6 | U-0.022 | U-0.022 | U-0.022 |
Continuous Insulation Uninterrupted by Framing |
No Framing | R-1.0 | U-0.425 | U-0.367 | U-0.324 |
| R-2.0 | U-0.298 | U-0.269 | U-0.245 |
| R-3.0 | U-0.230 | U-0.212 | U-0.197 |
| R-4.0 | U-0.187 | U-0.175 | U-0.164 |
| R-5.0 | U-0.157 | U-0.149 | U-0.141 |
No Framing | R-6.0 | U-0.136 | U-0.129 | U-0.124 |
| R-7.0 | U-0.120 | U-0.115 | U-0.110 |
| R-8.0 | U-0.107 | U-0.103 | U-0.099 |
| R-9.0 | U-0.097 | U-0.093 | U-0.090 |
| R-10.0 | U-0.088 | U-0.085 | U-0.083 |
No Framing | R-11.0 | U-0.081 | U-0.079 | U-0.076 |
| R-12.0 | U-0.075 | U-0.073 | U-0.071 |
| R-13.0 | U-0.070 | U-0.068 | U-0.066 |
| R-14.0 | U-0.065 | U-0.064 | U-0.062 |
| R-15.0 | U-0.061 | U-0.060 | U-0.059 |
No Framing | R-16.0 | U-0.058 | U-0.056 | U-0.055 |
| R-17.0 | U-0.054 | U-0.053 | U-0.052 |
| R-18.0 | U-0.052 | U-0.051 | U-0.050 |
| R-19.0 | U-0.049 | U-0.048 | U-0.047 |
| R-20.0 | U-0.047 | U-0.046 | U-0.045 |
No Framing | R-21.0 | U-0.045 | U-0.044 | U-0.043 |
| R-22.0 | U-0.043 | U-0.042 | U-0.042 |
| R-23.0 | U-0.041 | U-0.040 | U-0.040 |
| R-24.0 | U-0.039 | U-0.039 | U-0.038 |
| R-25.0 | U-0.038 | U-0.037 | U-0.037 |
No Framing | R-30.0 | U-0.032 | U-0.032 | U-0.031 |
| R-35.0 | U-0.028 | U-0.027 | U-0.027 |
| R-40.0 | U-0.024 | U-0.024 | U-0.024 |
| R-45.0 | U-0.022 | U-0.021 | U-0.021 |
| R-50.0 | U-0.019 | U-0.019 | U-0.019 |
| R-55.0 | U-0.018 | U-0.018 | U-0.018 |
| R-60.0 | U-0.016 | U-0.016 | U-0.016 |
Brick cavity wall with continuous insulation |
No Framing | R-0.0 | U-0.337 | U-0.299 | U-0.270 |
No Framing | R-3.8 | U-0.148 | U-0.140 | U-0.133 |
No Framing | R-5.0 | U-0.125 | U-0.120 | U-0.115 |
No Framing | R-6.5 | U-0.106 | U-0.102 | U-0.098 |
No Framing | R-7.6 | U-0.095 | U-0.091 | U-0.088 |
No Framing | R-10.0 | U-0.077 | U-0.075 | U-0.073 |
No Framing | R-10.5 | U-0.079 | U-0.077 | U-0.075 |
No Framing | R-11.4 | U-0.070 | U-0.068 | U-0.066 |
No Framing | R-15.0 | U-0.056 | U-0.055 | U-0.053 |
No Framing | R-16.5 | U-0.054 | U-0.053 | U-0.052 |
No Framing | R-19.0 | U-0.046 | U-0.045 | U-0.044 |
No Framing | R-22.5 | U-0.041 | U-0.040 | U-0.039 |
No Framing | R-28.5 | U-0.033 | U-0.032 | U-0.032 |
Continuous Insulation Uninterrupted by Framing with Stucco and Continuous Metal Framing at 24 in. on center horizontally |
1.0 in. | R-0.0 + R-19 c.i. | U-0.047 | U-0.046 | U-0.045 |
1.0 in. | R-3.8 + R-19 c.i. | U-0.045 | U-0.044 | U-0.044 |
1.0 in. | R-5.0 + R-19 c.i. | U-0.045 | U-0.044 | U-0.043 |
1.0 in. | R-6.5 + R-19 c.i. | U-0.045 | U-0.044 | U-0.043 |
1.5 in. | R-11.0 + R-19 c.i. | U-0.044 | U-0.043 | U-0.043 |
2.0 in. | R-7.6 + R-19 c.i. | U-0.043 | U-0.042 | U-0.041 |
2.0 in. | R-10.0 + R-19 c.i. | U-0.042 | U-0.041 | U-0.041 |
2.0 in. | R-13.0 + R-19 c.i. | U-0.042 | U-0.041 | U-0.041 |
3.0 in. | R-11.4 + R-19 c.i. | U-0.041 | U-0.040 | U-0.039 |
3.0 in. | R-15.0 + R-19 c.i. | U-0.040 | U-0.039 | U-0.039 |
3.0 in. | R-19.0 + R-19 c.i. | U-0.040 | U-0.039 | U-0.038 |
3.5 in. | R-11.0 + R-19 c.i. | U-0.040 | U-0.039 | U-0.039 |
3.5 in. | R-13.0 + R-19 c.i. | U-0.040 | U-0.039 | U-0.038 |
5.0 in. | R-19.0 + R-19 c.i. | U-0.037 | U-0.036 | U-0.036 |
5.0 in. | R-25.0 + R-19 c.i. | U-0.036 | U-0.035 | U-0.035 |
5.0 in. | R-32.5 + R-19 c.i. | U-0.035 | U-0.035 | U-0.034 |
5.5 in. | R-19.0 + R-19 c.i. | U-0.036 | U-0.036 | U-0.035 |
5.5 in. | R-21.0 + R-19 c.i. | U-0.035 | U-0.035 | U-0.035 |
Note for Default Table A103.3.7.1(2):
a. | It is acceptable to use the U-factors in Table A103.3.7.1(2) for all concrete and masonry walls, provided that the grouting is equal to or less than that specified. |
| - For ungrouted walls, use the partially grouted column. |
| - For metal studs and z-furring, use the continuous-metal-framing category. |
| - For discontinuous metal clips 1 inch square or smaller, use the metal-clip category. |
| - For insulation that is attached without any framing members (e.g. glued), use the continuous-insulation uninterrupted-by-framing category. Continuous insulation may be installed on the interior or exterior of masonry walls, or between stand-alone walls in multilayer masonry walls, or on the interior or exterior of the concrete. |
b. | For Table A103.3.7.1(2), the U-factor includes R-0.17 for exterior air film and R-0.68 for interior air film-vertical surfaces. For insulated walls, the U-factor also includes R-0.45 for 0.5 in. gypsum board. U-factors are provided for the following configurations: |
| (1) Concrete wall: 8-in. normal weight concrete wall with a density of 145 lb/ft3. |
| (2) Solid grouted concrete block wall: 8-in. medium weight ASTM C90 concrete block with a density of 115 lb/ft3 and solid grouted cores. |
| (3) Partially grouted concrete block wall: 8-in. medium weight ASTM C90 concrete block with a density of 115 lb/ft3 having reinforcing steel every 32 in. vertically and every 48 in. horizontally, with cores grouted in those areas only. Other cores are filled with insulating material only if there is no other insulation. |
c. | For walls with insulation contained in a framing layer, the U-factors in Table A103.3.7.1(2) assume contact (and thermal bridging) between the mass wall and other framing. For wall assemblies with multiple layers where the wood or metal framing layer does not contact the concrete or masonry layer (i.e., walls with an airspace between the stud wall layer and the mass wall layer), it is acceptable to use the appropriate wood or metal frame wall default U-factors in Tables A103.3.1 or A103.3.6.1. Note: It is acceptable to use this approach where the insulation extends beyond the framing and is in contact with the mass wall layer (e.g. a nominal four-inch metal stud containing insulation that is nominally six inches thick and therefore extends two inches beyond the back of the metal stud). |
d. | Except for wall assemblies qualifying for note 3, if not taken from Table A103.3.7.1(2), mass wall U-factors shall be determined in accordance with ASHRAE 90.1, Appendix A, Section A3.1 and Tables A3.1A to A3.1D, or Section A9.4. |
A103.3.7.2 Peripheral edges of intermediate concrete floors. See Table A103.3.7.2.
Table A103.3.7.2
Default U-factors for Peripheral Edges of Intermediate Concrete Floorsa, b, c
| Average Thickness of Wall above and below |
Slab Edge Treatment | 6 inches | 8 inches | 10 inches | 12 inches |
Exposed Concrete | 0.816 | 0.741 | 0.678 | 0.625 |
R-5 Exterior Insulation | 0.161 | 0.157 | 0.154 | 0.152 |
R-6 Exterior Insulation | 0.138 | 0.136 | 0.134 | 0.132 |
R-7 Exterior Insulation | 0.122 | 0.120 | 0.118 | 0.116 |
R-8 Exterior Insulation | 0.108 | 0.107 | 0.106 | 0.104 |
R-9 Exterior Insulation | 0.098 | 0.097 | 0.095 | 0.094 |
R-10 Exterior Insulation | 0.089 | 0.088 | 0.087 | 0.086 |
R-11 Exterior Insulation | 0.082 | 0.081 | 0.080 | 0.079 |
R-12 Exterior Insulation | 0.076 | 0.075 | 0.074 | 0.074 |
R-13 Exterior Insulation | 0.070 | 0.070 | 0.069 | 0.068 |
R-14 Exterior Insulation | 0.066 | 0.065 | 0.065 | 0.064 |
R-15 Exterior Insulation | 0.062 | 0.061 | 0.061 | 0.060 |
Note for Table A103.3.7.2:
a. | Exterior insulation values listed above are continuous R-values on the exterior side of the concrete floor. |
b. | For conditions with an exterior wall above the peripheral edge of intermediate concrete floor but with no wall below the intermediate concrete floor this table may be used as long as the code minimum insulation is applied to the floor slab below the concrete floor. |
c. | Typical conditions where conditioned space building envelope wall thermal insulation values are broken concrete floors include, but are not limited to, the following examples: |
| 1. Elevator hoistway shafts that serve the conditioned building and pass through unconditioned floors such as parking garage levels; |
| 2. Stairwell enclosures that serve the conditioned building and pass through unconditioned floors such as parking garage levels; |
| 3. Walls between interior and exterior building envelope that separate the interior conditioned space from an exterior courtyard or roofdeck; |
| 4. Walls between interior and exterior building envelope that separate the interior conditioned space from an exterior unconditioned space on parking garage levels. |
[Statutory Authority: RCW
19.27A.025,
19.27A.045,
19.27A.160 and
19.27.074. WSR 16-13-088, § 51-11C-610337, filed 6/15/16, effective 7/16/16. Statutory Authority: RCW
19.27A.025,
19.27A.160, and
19.27.074. WSR 16-03-072, § 51-11C-610337, filed 1/19/16, effective 7/1/16. Statutory Authority: RCW
19.27A.020,
19.27A.025 and chapters
19.27 and
34.05 RCW. WSR 13-04-056, § 51-11C-610337, filed 2/1/13, effective 7/1/13.]
