Table 14 Solar Absorptivity
|
Material
|
Absorption
|
|
|
|
|
Bricks
|
|
|
White glazed
|
0.25
|
|
Fletton light
|
0.4
|
|
Fletton dark
|
0.65
|
|
Stafford blue
|
0.9
|
|
White sand lime
|
0.4-0.5
|
|
Red sand lime
|
0.55-0.7
|
|
|
|
|
Stone
|
|
|
Limestone
|
0.3-0.5
|
|
White marble
|
0.45
|
|
Red granite
|
0.55
|
|
|
|
|
Roofs
|
|
|
Concrete tiles
|
0.65
|
|
Asphalt
|
0.9
|
|
Grey slates
|
0.8-0.9
|
|
Red tiles
|
0.4-0.8
|
|
Asbestos sheets, natural colour
|
0.6
|
|
Galvanised iron
|
0.65
|
|
Lead sheeting
|
0.8
|
|
Mortar screed
|
0.8
|
|
Aluminium
|
0.2
|
|
Copper (tarnished)
|
0.65
|
|
Whitewashed roof or white tile
|
0.3-0.5
|
|
|
|
|
Water
|
|
|
1 m thick
|
0.56
|
|
2 m thick
|
0.61
|
|
3 m thick
|
0.64
|
|
|
|
|
Dirty surfaces
|
|
|
Light when clean
|
0.5
|
|
Medium when clean
|
0.8
|
|
Dark when clean
|
0.9
|
