Civil Engineering Reference
In-Depth Information
been replaced with houses with concrete floors covered in plastic tiles. The com-
plaints developed into minor damage to muscles and joints - the hard floors were the
cause.
In the same way, over hundreds of years, horses used in the towns and cities suffered
as a result of the hard surfaces under their hooves. They were put out to graze much ear-
lier than country horses, used to working on a softer surface.
'Bakers' illness' was once a common problem in bakeries with hard concrete and tiled
floors. These were in direct contact with the ovens, which warmed the floor by up to
30°C. The continual high floor temperature gave bakers headaches and feelings of
tiredness. One way to avoid this was through wearing wooden clogs, as wood is a bad
thermal conductor. A more common and serious problem today is high thermal con-
ductivity in floors, which draw warmth out of the feet. A concrete floor will almost always
feel cold.
Floors made of materials that are bad electrical conductors as PVC (see Table 15.1)
create an electrostatic charge when rubbed which attracts dust particles out of the air. This
is one of the most likely reasons for 'sick building syndrome'.
Metal surface materials
There are metal alternatives to all surface materials. Roof sheeting of galvanized
steel and aluminium are increasingly being used as roofing in many building
types, large and small. Different forms of metal cladding are also in use as exter-
nal wall surfaces.
In industrial buildings the internal wall cladding is often made of stainless
steel. This is easy to keep clean and particularly well-suited to premises that pro-
duce food. Flooring consisting of 6-8 mm-thick cast iron tiles with a textured sur-
face is suitable for use in buildings used for heavy industry. Historic examples of
the internal use of metal sheeting are limited. One example is the notorious lead
chambers of Venice which were used for jailing particularly dangerous criminals
such as the seducer Don Juan. The lead chambers were placed on roofs exposed
to the sun, making them unbearably hot during the day and terribly cold at
night.
Many metals can be used for roof covering and external cladding. Copper
and bronze have been widely used on churches and other prestigious build-
ings. In the south west of England, lead from local mines is used as a roof
material. In Iceland, walls and roofs covered with corrugated iron imported
from England have been part of the established building tradition since the
1890s.
Modern metal sheeting is mainly made of galvanized steel, aluminium, cop-
per, zinc and stainless steel. As far as internal use is concerned, stainless steel
totally dominates the market. The products are often anodized with a thin
surface layer or painted with special plastic paints. Linseed oil can be used to
protect steel and zinc products. Certain metals cannot be used together because
