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Junction ψ-values and f-values (walls with fully filled cavities)

Thermal bridging ψ-values and f-values for walls fully filled with mineral wool thermal insulation.

The models given in this document cover:

Ultralightweight aggregate blocks with λ not exceeding 0.28 W/mK
Lightweight aggregate blocks with λ not exceeding 0.60 W/mK
Dense aggregate blocks with λ not exceeding 1.33 W/mK

Summary of ψ-values

SAP 2012 Table K1 ref: E1

Junction Detail: Steel lintel with perforated steel base plate
SAP2012 Approved ψ-value (W/mK): 0.50
SAP2012 Default ψ-value (W/mK): 1.00
Calculated CBA Full-fill ψ-value (W/mK):
Ultra-lightweight: 0.292 to 0.313
Lightweight: 0.346 to 0.358
Dense: 0.390 to 0.408
CBA detail ref: E1 FF CBA-312A

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SAP 2012 Table K1 ref: E1

Junction Detail: Keystone Hi Therm Lintel HTS 100 & 150
SAP2012 Approved ψ-value (W/mK): 0.50
SAP2012 Default ψ-value (W/mK): 1.00
Calculated CBA Full-fill ψ-value (W/mK):
Ultra-lightweight: 0.030 to 0.050
Lightweight: 0.028 to 0.049
Dense: 0.027 to 0.049
CBA detail ref: E1 FF CBA-312

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SAP 2012 Table K1 ref: E2
Junction Detail: Other lintels (including other steel lintels)
SAP2012 Approved ψ-value (W/mK): 0.30
SAP2012 Default ψ-value (W/mK): 1.00
Calculated CBA Full-fill ψ-value (W/mK): Ultra-lightweight: 0.020 to 0.028
Lightweight: 0.018 to 0.024
Dense: 0.017 to 0.021
CBA detail ref: E2 FF CBA-313

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SAP 2012 Table K1 ref: E3
Junction Detail: Sill
SAP2012 Approved ψ-value (W/mK): 0.04
SAP2012 Default ψ-value (W/mK): 0.08
Calculated CBA Full-fill ψ-value (W/mK): Ultra-lightweight: 0.015 to 0.021
Lightweight: 0.013 to 0.020   Dense: 0.013 to 0.021    CBA detail ref: E3 FF CBA-314

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SAP 2012 Table K1 ref: E4
Junction Detail: Jamb
SAP2012 Approved ψ-value (W/mK): 0.05
SAP2012 Default ψ-value (W/mK): 0.10
Calculated CBA Full-fill ψ-value (W/mK):  Ultra-lightweight: 0.010 to 0.017
Lightweight: 0.009 to 0.016
Dense: 0.008 to 0.016
CBA detail ref: E4 FF CBA-315

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SAP 2012 Table K1 ref: E5
Junction Detail: Ground Floor (Normal)
SAP2012 Approved ψ-value (W/mK): 0.16
SAP2012 Default ψ-value (W/mK): 0.32
Calculated CBA Full-fill ψ-value (W/mK): Ultra-lightweight: 0.056 to 0.065
Lightweight: 0.091 to 0.108
Dense: 0.145 to 0.178
CBA detail ref: E5 FF CBA-301

Cert 301 – Beam and block
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Cert 302 – Slab on ground
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SAP 2012 Table K1 ref: E6
Junction Detail: Intermediate floor within a dwelling
SAP2012 Approved ψ-value (W/mK): 0.07
SAP2012 Default ψ-value (W/mK): 0.14
Calculated CBA Full-fill ψ-value (W/mK): Ultra-lightweight: 0.000 to 0.001
Lightweight: 0.000
Dense: 0.000 to 0.002
CBA detail ref: E6 FF CBA-303

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SAP 2012 Table K1 ref: E7
Junction Detail: Intermediate floor between dwellings*
SAP2012 Approved ψ-value (W/mK): 0.07
SAP2012 Default ψ-value (W/mK): 0.14
Calculated CBA Full-fill ψ-value (W/mK): Ultra-lightweight: 0.0.65 to 0.104
Lightweight: 0.065 to 0.105
Dense: 0.066 to 0.108
CBA detail ref: E7 FF CBA-304

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SAP 2012 Table K1 ref: E10
Junction Detail: Eaves (Insulation at Ceiling Level)
SAP2012 Approved ψ-value (W/mK): 0.06
SAP2012 Default ψ-value (W/mK): 0.12
Calculated CBA Full-fill ψ-value (W/mK): Ultra-lightweight: 0.101 to 0.115
Lightweight: 0.106 to 0.122
Dense: 0.110 to 0.127
CBA detail ref: E10 FF CBA-308

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SAP 2012 Table K1 ref: E11
Junction Detail: Eaves (insulation at rafter level)
SAP2012 Approved ψ-value (W/mK): 0.04
SAP2012 Default ψ-value (W/mK): 0.08
Calculated CBA Full-fill ψ-value (W/mK): Ultra-lightweight: -0.005 to 0.007
Lightweight: -0.007 to 0.007
Dense: -0.006 to 0.008
CBA detail ref: E11 FF CBA-309

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SAP 2012 Table K1 ref: E12
Junction Detail: Gable (insulation at ceiling level)
SAP2012 Approved ψ-value (W/mK): 0.24
SAP2012 Default ψ-value (W/mK): 0.48
Calculated CBA Full-fill ψ-value (W/mK): Ultra-lightweight: 0.050 to 0.058
Lightweight: 0.077 to 0.087
Dense: 0.116 to 0.132
CBA detail ref: E12 FF CBA-310

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SAP 2012 Table K1 ref: E13
Junction Detail: Gable (insulation at rafter level)
SAP2012 Approved ψ-value (W/mK): 0.04
SAP2012 Default ψ-value (W/mK): 0.08
Calculated CBA Full-fill ψ-value (W/mK): Ultra-lightweight: 0.055 to 0.059
Lightweight: 0.073 to 0.076
Dense: 0.088 to 0.091
CBA detail ref: E13 FF CBA-311

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SAP 2012 Table K1 ref: E16
Junction Detail: Corner (normal)
SAP2012 Approved ψ-value (W/mK): 0.09
SAP2012 Default ψ-value (W/mK): 0.18
Calculated CBA Full-fill ψ-value (W/mK): Ultra-lightweight: 0.046 to 0.059
Lightweight: 0.051 to 0.068
Dense: 0.054 to 0.074
CBA detail ref: E16 FF CBA-316

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SAP 2012 Table K1 ref: E17
Junction Detail: Corner (inverted – internal wall area greater than external area)
SAP2012 Approved ψ-value (W/mK): -0.09
SAP2012 Default ψ-value (W/mK): 0.00
Calculated CBA Full-fill ψ-value (W/mK): Ultra-lightweight: -0.111 to -0.067
Lightweight: -0.119 to -0.070
Dense: -0.112 to -0.070
CBA detail ref: E17 FF CBA-317

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SAP 2012 Table K1 ref: E18
Junction Detail: Party (separating) wall between dwellings*
SAP2012 Approved ψ-value (W/mK): 0.03
SAP2012 Default ψ-value (W/mK): 0.06
Calculated CBA Full-fill ψ-value (W/mK): Ultra-lightweight: 0.055 to 0.087
Lightweight: 0.056 to 0.092
Dense: 0.058 to 0.096
CBA detail ref: E18 FF CBA-305

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SAP 2012 Table K1 ref: E20
Junction Detail: Exposed Floor (Normal)
SAP2012 Default ψ-value (W/mK): 0.32
Calculated CBA Full-fill ψ-value (W/mK):

Ultra-lightweight: 0.138 to 0.159   Lightweight: 0.204 to 0.220   Dense: 0.310 to 0.317    CBA detail ref: E20-C-A1 Timber floor over garage or drive-through/side wall

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Ultra-lightweight: 0.226 to 0.239   Lightweight: 0.233 to 0.245   Dense: 0.241 to 0.254    CBA detail ref: E20-C-A2 Concrete floor over drive- through/side wall

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Ultra-lightweight: 0.090 to 0.178   Lightweight: 0.092 to 0.232   Dense: 0.095 to 0.293    CBA detail ref: E20-C-A3 Concrete floor over garage or drive-through / opening

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Ultra-lightweight: 0.076 to 0.082   Lightweight: 0.129 to 0.140   Dense: 0.225 to 0.243    CBA detail ref: E20-T-A1 Timber floor over garage/side wall

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Ultra-lightweight: 0.101 to 0.108   Lightweight: 0.142 to 0.150   Dense: 0.1910 to 0.200    CBA detail ref: E20-T-A2 Timber floor over drive-through/side wall

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Ultra-lightweight: 0.139 to 0.150   Lightweight: 0.139 to 0.151   Dense: 0.139 to 0.151    CBA detail ref: E21-T-A2 Timber floor over drive-through/side wall

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SAP 2012 Table K1 ref: E21
Junction Detail: Exposed floor (inverted)
SAP2012 Default ψ-value (W/mK): 0.32
Calculated CBA Full-fill ψ-value (W/mK):

Ultra-lightweight: 0.146 to 0.052   Lightweight: 0.0127 to 0.132   Dense: 0.252 to 0.256    CBA detail ref: E21-C-A1 Concrete floor over garage/side wall

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Ultra-lightweight: 0.163 to 0.168   Lightweight: 0.162 to 0.167   Dense: 0.163 to 0.167    CBA detail ref: E21-C-A2 Concrete floor over drive-through/side wall

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Ultra-lightweight: 0.055 to 0.065   Lightweight: 0.115 to 0.127   Dense: 0.192 to 0.250    CBA detail ref: E21-T-A1 Timber floor over garage/side wall

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Ultra-lightweight: 0.139 to 0.150   Lightweight: 0.139 to 0.151   Dense: 0.139 to 0.151    CBA detail ref: E21-T-A2 Timber floor over drive-through/side wall

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SAP 2012 Table K1 ref: E24
Junction Detail: Eaves (Insulation at ceiling level – inverted)*
SAP2012 Default ψ-value (W/mK): 0.24
Calculated CBA Full-fill ψ-value (W/mK):

Ultra-lightweight: 0.090 to 0.105   Lightweight: 0.087 to 0.103   Dense: 0.087 to 0.104    CBA detail ref: E24-1-C-A Pitched roof over addition/concrete lintel

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Ultra-lightweight: 0.111 to 0.148   Lightweight: 0.110 to 0.148   Dense: 0.110 to 0.150    CBA detail ref: E24-1-S-A Pitched roof over addition/steel lintel

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Ultra-lightweight: 0.102 to 0.117   Lightweight: 0.099 to 0.118   Dense: 0.098 to 0.116    CBA detail ref: E24-2-C-A Pitched roof over bay/concrete lintel

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Ultra-lightweight: 0.165 to 0.170   Lightweight: 0.167 to 0.171   Dense: 0.169 to 0.174    CBA detail ref: E24-2-S-A Pitched roof over bay/steel lintel

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Ultra-lightweight: 0.189 to 0.219   Lightweight: 0.189 to 0.219   Dense: 0.189 to 0.219    CBA detail ref: E24-3-C-A Stepped apartment/concrete floor

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Ultra-lightweight: 0.181 to 0.206   Lightweight: 0.181 to 0.206   Dense: 0.181 to 0.207    CBA detail ref: E24-3-T-A Stepped apartment/timber floor

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SAP 2012 Table K1 ref: E25
Junction Detail: Staggered separating wall between dwellings*
SAP2012 Default ψ-value (W/mK): 0.12
Calculated CBA Full-fill ψ-value (W/mK):

Ultra-lightweight: 0.097 to 0.138   Lightweight: 0.0103 to 0.152   Dense: 0.108 to 0.161    CBA detail ref: E25-338-A 338mm stagger

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Ultra-lightweight: 0.093 to 0.145   Lightweight: 0.098 to 0.152   Dense: 0.099 to 0.156    CBA detail ref: E25-1038-A 1038mm stagger

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SAP 2012 Table K1 ref: P8
Junction Detail: Exposed floor (inverted)*
SAP2012 Default ψ-value (W/mK): 0.24
Calculated CBA Full-fill ψ-value (W/mK):

Ultra-lightweight: 0.089 to 0.099   Lightweight: 0.163 to 0.177   Dense: 0.274 to 0.293    CBA detail ref: P8-C-A1 Concrete floor over garage

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Ultra-lightweight: 0.196 to 0.210   Lightweight: 0.195 to 0.209   Dense: 0.1958 to 0.210    CBA detail ref: P8-C-A2 Concrete floor over drive-through

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Ultra-lightweight: 0.139 to 0.198   Lightweight: 0.162 to 0.247   Dense: 0.180 to 0.291    CBA detail ref: P8-T-A1 Timber floor over garage

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Ultra-lightweight: 0.171 to 0.263   Lightweight: 0.168 to 0.262   Dense: 0.168 to 0.260    CBA detail ref: P8-T-A2 Timber floor over-drive through

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SAP 2012 Table K1 ref: P4
Junction Detail: Roof (insulation at ceiling level)*
SAP2012 Default ψ-value (W/mK): 0.24
Calculated CBA Full-fill ψ-value (W/mK): Lightweight: 0.181
Dense: 0.200
CBA detail ref: P4 FF CBA-306

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SAP 2012 Table K1 ref: P5
Junction Detail: Roof (insulation at rafter level)*
SAP2012 Default ψ-value (W/mK): 0.04
Calculated CBA Full-fill ψ-value (W/mK): Lightweight: 0.035
Dense: 0.045
CBA detail ref: P5 FF CBA-307

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