Washington Administrative Code › Title 51 - Enterprise Services, Department of (Building Code Council) › Chapter 51-11C - State Building Code adoption and amendment of the 2021 edition of the International Energy Conservation Code, Commercial › Section 51-11C-610336 - Section A103.3.6 - Metal stud walls

Current through Register Vol. 24-14, July 15, 2024
A103.3.6 Metal stud walls.
The nominal R-values in
				Tables A103.3.6.1 through A103.3.6.3 may be used for purposes of calculating
				metal stud wall section U-factors in lieu of the ASHRAE zone calculation method
				as provided in Chapter 27 of the ASHRAE Fundamentals Handbook.
A103.3.6.1 Metal stud wall, overall assembly
				U-factors.
Tables A103.3.6.1(1) and A103.6.1(2): Assumes metal studs
				spaced on 16 or 24 inch centers with insulation installed to fill wall
				cavities. Continuous rigid board insulation is applied without creating
				uninsulated voids in the wall assembly.
Table A103.3.6.1(1) Overall Assembly U-factors for Metal
				Stud Walls with Continuous Insulation
Cavity Insulation
Metal Framing
R-Value of Continuous Foam Board
							 Insulation
R-0
R-11
R-13
R-15
R-19
R-21
16" o.c.
R-0 (none)
0.352
0.132
0.124
0.118
0.109
0.106
R-1
0.260
0.117
0.111
0.106
0.099
0.096
R-2
0.207
0.105
0.100
0.096
0.090
0.087
R-3
0.171
0.095
0.091
0.087
0.082
0.080
R-4
0.146
0.087
0.083
0.080
0.076
0.074
R-5
0.128
0.080
0.077
0.074
0.071
0.069
R-6
0.113
0.074
0.071
0.069
0.066
0.065
R-7
0.102
0.069
0.066
0.065
0.062
0.061
R-8
0.092
0.064
0.062
0.061
0.058
0.057
R-9
0.084
0.060
0.059
0.057
0.055
0.054
R-10
0.078
0.057
0.055
0.054
0.052
0.051
R-11
0.072
0.054
0.052
0.051
0.050
0.049
R-12
0.067
0.051
0.050
0.049
0.047
0.047
R-13
0.063
0.049
0.048
0.047
0.045
0.045
R-14
0.059
0.046
0.045
0.045
0.043
0.043
R-15
0.056
0.044
0.043
0.043
0.041
0.041
R-20
0.044
0.036
0.036
0.035
0.034
0.034
24" o.c.
R-0 (none)
0.338
0.116
0.108
0.102
0.094
0.090
R-1
0.253
0.104
0.098
0.092
0.086
0.083
R-2
0.202
0.094
0.089
0.084
0.079
0.077
R-3
0.168
0.086
0.082
0.078
0.073
0.071
R-4
0.144
0.079
0.075
0.072
0.068
0.066
R-5
0.126
0.073
0.070
0.067
0.064
0.062
R-6
0.112
0.068
0.066
0.063
0.060
0.059
R-7
0.100
0.064
0.062
0.059
0.057
0.055
R-8
0.091
0.060
0.058
0.056
0.054
0.052
R-9
0.084
0.057
0.055
0.053
0.051
0.050
R-10
0.077
0.054
0.052
0.050
0.048
0.048
R-11
0.072
0.051
0.049
0.048
0.046
0.045
R-12
0.067
0.048
0.047
0.046
0.044
0.043
R-13
0.063
0.046
0.045
0.044
0.042
0.042
R-14
0.059
0.044
0.043
0.042
0.041
0.040
R-15
0.056
0.042
0.041
0.040
0.039
0.038
R-20
0.044
0.035
0.034
0.034
0.033
0.032
Continuous foam board insulation: Continuous insulation assumes
				no thermal bridging of insulation by framing or z-furring through applied foam
				board. Zone calculation method as provided in the ASHRAE Fundamentals Handbook
				must be used for thermally bridged foam board insulation. Values for attachment
				of insulation with z-furring are given in Table A103.3.6.1(2).
Table A103.3.6.1(2) Overall Assembly U-factors for Metal
				Stud Walls with Insulation Supported by Z-furring
Cavity Insulation
Metal Framing
R-Value of Foam Board
Insulation
Z-furring Attachment
R-0
R-11
R-13
R-15
R-19
R-21
16" o.c.
R-0 (none)
Horizontal
0.352
0.132
0.124
0.118
0.109
0.106
R-5
Horizontal
0.155
0.089
0.086
0.083
0.078
0.077
R-7.5
Horizontal
0.128
0.080
0.077
0.074
0.071
0.069
R-10
Horizontal
0.110
0.072
0.070
0.068
0.065
0.064
R-12.5
Horizontal
0.099
0.068
0.065
0.064
0.061
0.060
R-15
Horizontal
0.091
0.064
0.062
0.060
0.058
0.057
R-17.5
Horizontal
0.084
0.060
0.058
0.057
0.055
0.054
R-20
Horizontal
0.078
0.057
0.056
0.054
0.052
0.052
R-22.5
Horizontal
0.074
0.055
0.054
0.052
0.051
0.050
R-25
Horizontal
0.071
0.053
0.052
0.051
0.049
0.048
R-0 (none)
Vertical
0.352
0.132
0.124
0.118
0.109
0.106
R-5
Vertical
0.165
0.093
0.089
0.086
0.081
0.079
R-7.5
Vertical
0.142
0.085
0.081
0.079
0.075
0.073
R-10
Vertical
0.126
0.079
0.076
0.074
0.070
0.069
R-12.5
Vertical
0.115
0.074
0.072
0.070
0.066
0.065
R-15
Vertical
0.107
0.071
0.069
0.067
0.064
0.063
R-17.5
Vertical
0.100
0.068
0.065
0.064
0.061
0.060
R-20
Vertical
0.094
0.065
0.063
0.061
0.059
0.058
R-22.5
Vertical
0.090
0.063
0.061
0.060
0.057
0.056
R-25
Vertical
0.086
0.061
0.059
0.058
0.056
0.055
24" o.c.
R-0 (none)
Horizontal
0.338
0.116
0.108
0.102
0.094
0.090
R-5
Horizontal
0.152
0.082
0.078
0.074
0.070
0.068
R-7.5
Horizontal
0.126
0.074
0.070
0.068
0.064
0.062
R-10
Horizontal
0.109
0.067
0.065
0.062
0.059
0.058
R-12.5
Horizontal
0.098
0.063
0.061
0.059
0.056
0.055
R-15
Horizontal
0.090
0.060
0.058
0.056
0.053
0.052
R-17.5
Horizontal
0.083
0.057
0.055
0.053
0.051
0.050
R-20
Horizontal
0.078
0.054
0.052
0.051
0.049
0.048
R-22.5
Horizontal
0.074
0.052
0.050
0.049
0.047
0.046
R-25
Horizontal
0.070
0.050
0.049
0.047
0.046
0.045
R-0 (none)
Vertical
0.338
0.116
0.108
0.102
0.094
0.090
R-5
Vertical
0.162
0.084
0.080
0.077
0.072
0.070
R-7.5
Vertical
0.140
0.078
0.074
0.071
0.067
0.065
R-10
Vertical
0.124
0.073
0.070
0.067
0.063
0.062
R-12.5
Vertical
0.113
0.069
0.066
0.064
0.061
0.059
R-15
Vertical
0.106
0.066
0.063
0.061
0.058
0.057
R-17.5
Vertical
0.098
0.063
0.061
0.059
0.056
0.055
R-20
Vertical
0.093
0.061
0.059
0.057
0.054
0.053
R-22.5
Vertical
0.089
0.059
0.057
0.055
0.053
0.051
R-25
Vertical
0.085
0.057
0.055
0.054
0.051
0.050
Values in Table A103.3.6.1(2) may not be interpolated between.
				The value of the foam board insulation must meet or exceed the value listed in
				the table in order to use the value shown.
A103.3.6.2 Metal stud wall, effective R-values for metal
				framing and cavity only.
Table A103.3.6.2: These values may be used for
				the metal-framing/cavity layers in walls with metal studs spaced on 16- or
				24-inch centers with insulation installed to fill wall cavities in lieu of
				using the zone method provided in Chapter 25 of the ASHRAE Fundamentals
				Handbook.
Table A103.3.6.2 Effective R-values for Metal Framing and
				Cavity Only
Cavity
Insulation
Nominal
Depth,
Inches
Actual
Depth,
Inches
Nominal
R-Value
Effective R-Value
16" O.C.
24" O.C.
Air
Cavity
any
any
R-0.91 (air)
0.79
0.91
4
3-1/2
R-11
5.5
6.6
4
3-1/2
R-13
6.0
7.2
Wall
4
3-1/2
R-15
6.4
7.8
6
5-1/2
R-19
7.1
8.6
6
5-1/2
R-21
7.4
9.0
8
7-1/4
R-25
7.8
9.6
Roof
Insulation is uncompressed
R-11
5.5
6.1
R-19
7.0
9.1
R-30
9.3
11.4
A103.3.6.3 Metal building wall.
Table A103.3.6.3:
				A wall whose structure consists of metal spanning panels supported by steel
				structural members (does not include spandrel glass or metal panels in curtain
				wall systems). The first nominal R-value is for insulation compressed between
				metal wall panels and the steel structure. For double-layer installations, the
				second rated R-value of insulation is for insulation installed from the inside,
				covering the girts. For continuous insulation (e.g., insulation boards) it is
				assumed that the insulation boards are installed on the inside of the girts and
				uninterrupted by the framing members. Insulation exposed to the conditioned
				space or semi-heated space shall have a facing, and all insulation seams shall
				be continuously sealed to provide a continuous air barrier.
Table A103.3.6.3 Default Metal Building Wall
				U-factors
Overall U-Factor for Assembly of Base Wall Plus
							 Continuous Insulation (Uninterrupted by Framing)
Insulation System
Rated R-Value of
Insulation
Overall U-Factor for Entire Base Wall
							 Assembly
R-6.5
R-13
R-19.5
R-26
R-32.5
R-39
Single Layer of Mineral Fiber
None
1.180
0.136
0.072
0.049
0.037
0.030
0.025
R-10
0.186
0.084
0.054
0.040
0.032
0.026
0.023
R-11
0.185
0.084
0.054
0.040
0.032
0.026
0.023
R-13
0.162
0.079
0.052
0.039
0.031
0.026
0.022
R-16
0.155
0.077
0.051
0.039
0.031
0.026
0.022
R-19
0.147
0.075
0.050
0.038
0.030
0.025
0.022
Statutory Authority:
				  RCW
				  19.27A.020,
				  19.27A.025 and
				  chapters
				  19.27 and
				  34.05 RCW. 13-04-056, §
				  51-11C-610336, filed 2/1/13, effective
				  7/1/13.