Civil Engineering Reference
In-Depth Information
18
Paint, varnish, stain and wax
Paint, varnish and stain are used to make a building more beautiful. Traditional
painting of buildings has to a great extent revealed a wish to imitate other more
noble building materials. The light yellow and grey render or timber façade has
imitated light stone façades of marble, lime or sandstone; dark red façades have
imitated brick. Colour has in this way had an outward-looking, representational
function. But it can be used in the same way inside.
Theo Gimbel is a well-known colour therapist with his own school in England.
He believes that colours start chemical processes within us, and that each cell is
a sort of eye that takes in colours. Hence blind people can also be treated with
colour. Red helps tiredness and bad moods, but should be avoided by those with
heart problems. Yellow stimulates the brain. Green has a quieting effect, and vio-
let strengthens creativity and spirituality.
Colour coatings are also thought to protect the material underneath. This
is not always the case: there are many examples of damage caused by surface
treatments, such as render and masonry that quickly began to decay after
treatment with vapour-proof paint or timber which is often attacked by
mould after painting. Research has shown that the decay of untreated timber
when exposed to ultraviolet radiation, wind and rain is relatively small. In
very exposed areas only about 1 mm is worn down in 10 years; in normal
weather conditions 1 mm is eroded in 10-100 years. A much more significant
protection than even the most careful painting is obtained by the structural
protection of materials (see 'Structural protection of exposed components',
p. 431).
The most relevant justification for painting a house is aesthetic. Exceptions
are internal surfaces such as the floor, frames and certain details where treat-
ment with oils and waxes will ease cleaning and reduce wear. Colour can also
be used to lighten wood panelling which, with the exception of aspen, lime
and the sapwood of ash, will darken with time. Special paints are used for
