Civil Engineering Reference
In-Depth Information
which can often contain lead and cadmium, are also added. The usual softeners
are di-oktylphtalate (DOP) and di(2-ethylhexyl)phtalate (DEHP). PVC coverings
are hard and usually lie on a soft underlay of jute matting, polyester fibres, cork,
foamed PVC or fibreglass.
Polyolephine covering
This is produced from ethylene and propylene. No softener is used, but stabiliz-
ers, fire retardants and colour pigments are added. It also has acrylate on its sur-
face coating.
Synthetic rubber covering
This is based on styrene-butadiene-rubber (SBR) and has many additives: stabi-
lizers, fire-retardants, vulcanizing agents and softeners.
These products are all based on oil which is a very limited resource. The prima-
ry energy consumption for all of the products is very high. In all phases, from
production through use to waste, these products present pollution risks. In the
indoor climate there is a high chance of the mucous membranes being irritated.
The polyolephine flooring causes the fewest problems. From a newly laid PVC
floor, up to 62 different substances are emitted, including solvents and phtha-
lates. Phthalates are emitted for as long as the building stands, and there is clear
evidence of a relationship between the occurrence of DEHP and asthma in chil-
dren (Øye, 1998). Extremely high emissions have been measured from vinyl
flooring on concrete because the alkali increases the breakdown of substances,
including phenol emissions in some cases (Gustafsson, 1990). SBR flooring has
been known to emit styrene and butadiene.
Floor coverings of PVC and SBR will shrink somewhat as the softeners evapo-
rate, and damage can occur in the joints which makes them dirt traps and an
attractive breeding ground for fungus. On all plastic surfaces, which are not
moisture absorbers, the production of bacteria is generally 30 times greater than
the equivalent damp absorbing surface, such as timber. Plastic flooring can nor-
mally also become highly electrostatically charged.
PVC and polyolephine floorings can be recycled, theoretically, but it is highly
unlikely that this will occur in practice because of the difficulty of removing the
material. SBR flooring cannot be recycled. Polyolephine flooring can probably be
energy recycled at plants with particular filter systems for the fumes. All waste
must be specially disposed of.
Carpets and textiles
Carpet as a floor covering has a particular function, providing a more comfort-
able surface to walk on. It is soft, has little thermal conductivity and a good noise
