Civil Engineering Reference
In-Depth Information
quality floor as long as it is given a smooth and dust-binding finish. Earth from
the immediate vicinity should be used. It is rammed to the right consistency
and the surface can be treated or covered with another finish. The use of ener-
gy is very low, and the floor returns to its original state when the building
dilapidates, as it has not been chemically treated. For the users, earth makes a
relatively warm floor, and it is soft and comfortable to walk on. Earth is the
most widespread floor surface, world-wide, and the most ecological floor con-
ceivable!
Laying an earth floor
The underlay must be well-drained, dry and firm, e.g. a 20-25 cm thick layer of light
expanded clay fill. Light clay fill must be well bound with a lime-cement gruel. An alterna-
tive is a bound layer of crushed stone. Fine chicken net is placed on top of this. The floor
should be rammed to a depth of 15-20 cm, in
lengths 1 m wide
, bordered by a plank,
using the same technique and equipment used in wall ramming. Ten centimetres can be
laid at a time. The earth should be the same quality as for Pisé building. The top layer
must be well-sieved earth, and when it has been rammed, the surface should be evened
out with a long-handled scraper.
If the floor is to be an underlay for a timber floor on battens, cork, linoleum, coconut or
sisal mats, it has to dry out for a year before being covered.
If the floor is to be exposed it will be easier to maintain if it is rendered with an elastic
mortar. In this case, fibres should be added to increase elasticity.
Plastic-based sheet materials
Sheet products in plastic are limited to building sheets, floor coverings, carpets
and textile and wall coverings. Except for building sheets, the rest are discussed
towards the end of this chapter.
The sheets are usually composite products consisting of sheets of paper sprin-
kled with a plastic, usually a phenol or melamine (about 25 per cent by weight),
pressed together under high pressure and heated. These products are mainly
used for wall and ceiling cladding, without any further treatment. A stronger
sheet can be made with polyester and a mixture of stone particles reinforced with
fibreglass.
Plastic products are based on oil, a very limited resource, the extraction of
which creates high levels of pollution and is high risk. Their manufacture is ener-
gy-intensive and polluting. There is a strong chance that emissions from these
products enter the indoor climate, depending upon how well the plastic has been
cured.
These surface products and composite materials can seldom be recycled.
Sheets with a high proportion of paper can be burned for energy recycling, but
