- Example U Value Calculation -
Typical Orlit Property
 
 
Construction Type
Element: Wall - Concrete Panel
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
-
-
Precast concrete panel
52.00
1.400
0.037
200.00
10.40
Cavity
-
-
0.180
-
-
Lightweight precast concrete
65.00
0.400
0.163
40.00
2.60
Timber stud cavity
-
-
0.100
-
-
Plasterboard
13.00
0.167
0.078
45.00
0.059
Plaster scrim coat
3.00
0.160
0.019
50.00
0.15
Inside surface resistance
-
-
0.130
U-Value, Proportionate Area Method:
1.339 (W/m²K)


60mm 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
60.00
0.028
2.143
0.00
0.00
Precast concrete panel
52.00
1.400
0.037
200.00
10.40
Cavity
-
-
0.180
-
-
Lightweight precast concrete
65.00
0.400
0.163
40.00
2.60
Timber stud cavity
-
-
0.100
-
-
Plasterboard
13.00
0.167
0.078
45.00
0.059
Plaster scrim coat
3.00
0.160
0.019
50.00
0.15
Inside surface resistance
-
-
0.130
U-Value, Proportionate Area Method:
0.336 (W/m²K)


50mm 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
2.381
0.00
0.00
Precast concrete panel
52.00
1.400
0.037
200.00
10.40
Cavity
-
-
0.180
-
-
Lightweight precast concrete
65.00
0.400
0.163
40.00
2.60
Timber stud cavity
-
-
0.100
-
-
Plasterboard
13.00
0.167
0.078
45.00
0.059
Plaster scrim coat
3.00
0.160
0.019
50.00
0.15
Inside surface resistance
-
-
0.130
U-Value, Proportionate Area Method:
0.327 (W/m²K)



 

Line Break

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.