Civil Engineering Reference
In-Depth Information
Table 14.5:
The use of timber climatic products in building
Material
Composition
Areas of use
Timber panelling
(1)
Untreated timber
Balancing of relative humidity
Woodchip, possibly with lime, sand,
magnesium chloride, waterglass,
borax, ammonia polyphosphate
Thermal insulation, balancing of
relative humidity
Woodchip
Cork oak which can also be mixed
with bitumen or gelatine
Thermal insulation, balancing of
relative humidity
Cork
Wood strands bound with cement or
magnesite
Thermal insulation, thermal storage,
balancing of relative humidity, sound
absorption, sound insulation
Woodwool slabs
Mass of wood fibres with paper with
or without bitumen
Thermal insulation, wind-proofing,
balancing of relative humidity, sound
absorption
Porous fibreboard
Mass of wood fibres, can have
bitumen coating
Vapour barrier
Hard fibreboard
Cellulose with borax or boric acid,
and/or aluminium hydroxide
Thermal insulation, balancing of
relative humidity, wind-proofing
Cellulose fibre loose
or matting
Cellulose, glue, in certain cases
bitumen, silicone or latex
Thermal insulation, balancing of
relative humidity, wind-proofing
Building
paper/cardboard
Pieces of bark from birch
Waterproofing, balancing of relative
humidity
Bark from birch
Note:
(1) See 'Timber Cladding', p. 344.
Table 14.6 shows that sawdust has a lower thermal insulation value, the
less dense it is, whereas the situation is the exact opposite with wood shav-
ings. Differences between the degrees of compression are so large that it
would be advisable to carry out test stamping and weighing before starting
work.
It is also possible to insulate thermally with ground sawdust otherwise used
for the production of wood fibreboard and building board. This fine-particled
material can be blown into the structure and can produce thermal insulation
values equivalent to those of mineral wool and cellulose fibre, i.e. approxi-
mately 0.04 W/m°C. These products often contain ammonium polyphos-
phate, in a proportion of about 8 per cent, as a fire retardant. This is a rela-
tively harmless chemical which is also used as an artificial fertilizer. As a
waste product it has no pollution potential and can be used to improve the
quality of soil.
