- Example U Value Calculation -
Typical Tarran Bungalows
 
 
Construction Type
Element: Wall - Concrete Panel
Exposure: Normal
Internal Surface Emissivity: High
External Surface Emissivity: High
Building Use: Domestic House / Flat


Uninsulated
Thickness
Thermal Conductivity
Thermal Resistance
Vapour Resistivity
Vapour Resistance
 
(mm)
(W/m²K)
(m²K/W)
(MNs/gm)
(MNs/g)
Outside surface resistance
-
-
0.040
-
-
Concrete panel
32.00
1.391
0.023
100.00
3.20
Cavity
-
-
0.180
-
-
Plasterboard
12.50
0.167
0.075
45.00
0.56
Inside surface resistance
-
-
0.130
U-Value, Proportionate Area Method:
2.232 (W/m²K)


70mm PIR
Thickness
Thermal Conductivity
Thermal Resistance
Vapour Resistivity
Vapour Resistance
 
(mm)
(W/m²K)
(m²K/W)
(MNs/gm)
(MNs/g)
Outside surface resistance
-
-
0.040
-
-
WBS Polymer Cement Render
10.00
0.115
0.087
0.00
0.00
WBS PIR Insulation
70.00
0.028
2.500
0.00
0.00
Concrete panel
32.00
1.391
0.023
100.00
3.20
Cavity
-
-
0.180
-
-
Plasterboard
12.50
0.167
0.075
45.00
0.56
Inside surface resistance
-
-
0.130
U-Value, Proportionate Area Method:
0.329 (W/m²K)


60mm Phenolic
Thickness
Thermal Conductivity
Thermal Resistance
Vapour Resistivity
Vapour Resistance
 
(mm)
(W/m²K)
(m²K/W)
(MNs/gm)
(MNs/g)
Outside surface resistance
-
-
0.040
-
-
WBS Polymer Cement Render
10.00
0.115
0.087
0.00
0.00
WBS Phenolic Insulation
50.00
0.021
2.857
0.00
0.00
Concrete panel
32.00
1.391
0.023
100.00
3.20
Cavity
-
-
0.180
-
-
Plasterboard
12.50
0.167
0.075
45.00
0.56
Inside surface resistance
-
-
0.130
U-Value, Proportionate Area Method:
0.295 (W/m²K)



 

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Provided strictly for guidance purposes only. WBS accept no liability for errors or omissions.
For a full U-value calculation, including Condensation Risk Analysis and Temperature Profiles,
please contact WBS Technical Support on 08458 382380.