Introduction Part L CWCT guide Rating schemes Standards
Software CWCT research Theory Glossary Feedback





Links
Properties
 
 
 
Material properties

The table below lists the thermal conductivity ( -value) and the water vapour resistance factor (µ), taken from BS EN 12524:2000.
Material
Design thermal conductivity

[W/mK]
 Water vapour resistance factor
µ
Metals

Aluminium
160

Steel
50

Stainless steel
17

Iron
50

Zinc
110

Lead
35

Copper
380
Glass

Soda lime (float glass)
1.00


Quartz
1.40


Glass mosaic
1.20

Plastics, solid

Acrylic
0.20
10000

Polycarbonate
0.20
5000

PVC
0.17
50000

Polyamide
0.25
50000

Polyamide (reinforced)
0.30
50000

Polyurethane
0.25
6000
Rubber

Neoprene
0.23
10000

Butyl
0.25
200000

Foam rubber
0.06
7000

EPDM
0.25
6000

Polysulfide
0.40
10000
Sealant materials, weather stripping, thermal breaks

Silica gel
0.13


Silicone (pure)
0.35
5000

Silicon foam
0.12
10000

PVC (flexible)
0.14
100000

Polyurethane foam
0.05
60
Gypsum

Gypsum
0.18-0.56
4-10

Gypsum plasterboard
0.25
4-10
Plasters and renders

Gypsum insulating plaster
0.18
6-10

Gypsum plastering
0.40-0.57
6-10

Gypsum, sand
0.80
6-10

Lime, sand
0.80
6-10

Cement, sand
1.00
6-10
Timber

Hard wood
0.18
50-200

Soft wood
0.13
20-50

Top of page

    Thermal home Main CWCT pages Site map