- Example U Value Calculation -
225 Solid Brickwork
 
 
Construction Type
Element: Wall - 225mm Brickwork
Exposure: Normal
Internal Surface Emissivity: High
External Surface Emissivity: High
Building Use: Domestic House / Flat


Prior to WBS system application
Thickness
Thermal Conductivity
Thermal Resistance
Vapour Resistivity
Vapour Resistance
 
(mm)
(W/m²K)
(m²K/W)
(MNs/gm)
(MNs/g)
Outside surface resistance
-
-
0.040
-
-
Brick, medium weight external
225.00
0.752
0.299
50.00
11.25
Plaster, dense
13.00
0.500
0.026
60.00
0.78
Inside surface resistance
-
-
0.130
U-Value, Proportionate Area Method:
2.032 (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
100.00
1.00
WBS Phenolic Insulation
60.00
0.021
2.857
0.00
0.00
Brick, medium weight external
225.00
0.752
0.299
50.00
11.25
Plaster, dense
13.00
0.500
0.026
60.00
0.78
Inside surface resistance
-
-
0.130
U-Value, Proportionate Area Method:
0.291 (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
100.00
1.00
WBS PIR Insulation
70.00
0.028
2.500
0.00
0.00
Brick, medium weight external
225.00
0.752
0.299
50.00
11.25
Plaster, dense
13.00
0.500
0.026
60.00
0.78
Inside surface resistance
-
-
0.130
U-Value, Proportionate Area Method:
0.325 (W/m²K)

 

Line Break

Provided strictly for guidance purposes only.
For a full U-value calculation, including Condensation Risk Analysis and Temperature Profiles,
please contact WBS Technical Support on 08458 382380.