Civil Engineering Reference
In-Depth Information
Table 14.9:
Environmental profiles of thermal insulation
Quantity of
Specific
Specific
materials used
thermal
thermal
(kg/m
2
conductivity
capacity
thermal resistance
Material
(W/mK)
(kJ/kgK)
R = 3.75)
Still air
0.024
1.0
Water
0.50
1.9
Dry snow
0.06-0.47
Expanded perlite, untreated, 170 mm
0.045-0.055
3-4
13.5
Expanded perlite, with bitumen, 190 mm
0.055
3-4
15
Lightweight aggregate concrete blockwork (structural), 750 mm
0.210
1
560
Aerated concrete blockwork (structural), 400 mm
0.08
1
200
Foamglass boards, 170 mm
0.045
1.1
21
Foamglass granules, 350 mm
0.07
1
50
Mineral wool, 150 mm
0.04
0.8
3
Expanded clay pellets 430 mm
0.115
194
Expanded polyurethane 135 mm
0.035
1.5
3.8
Expanded and extruded polystyrene 150 mm
0.04
1.5
3.4
Expanded ureaformaldehyde, 180 mm
0.05
1.5
5
Compressed wood cuttings 200 mm
0.05-0.09
1.8
24
Porous fibreboard, unimpregnated, 200 mm
0.05
1.8
60
Wood wool slabs, 300 mm
0.08
1.9
69
Cellulose fibre, loose, 170 mm
0.045
approx 1.8
10.1
Cellulose fibre, matting, 150 mm
0.04
approx 1.8
11
Flaxen matting, 150 mm
0.04
approx 1.8
2.4
Slabs of peat, 150 mm
0.04
1.2
15
Straw bound together with clay, straw >100 kg/m
3
, 550 mm
0.12
1.2
330
Woollen matting, 150 mm
0.04
approx 1.8
3
Notes:
(1) This material also acts as a structural material, so no extra structure is needed.
(2) Thermal insulation varies a great deal with the different types of wood shavings/cuttings.
(3) If insecticide is added, much more care must be taken when this becomes waste.
chemicals are used for impregnation. To increase elasticity, polyester fibres are
added to some products.
The more dense felt products usually consist of wool, but can also contain
hair from cows and different plant fibres to keep the price reasonably low. Felt
is used as sound insulation between floor joists and as thermal insulation
around water pipes. It is also used, to a certain extent, as sealing around win-
dows.
Wool-based building paper consists of a good deal of recycled paper, but the
woollen content must not be lower than 15 per cent. Wool building paper is soft
