HEALTH AND SANITATION
51
There is a vast array of roof shapes (Figure 4.2) and
they tend to vary greatly from region to region. The
main factors which influence the shape of roofs are the
climate, the materials available for roof structure, and
the outer covering. Roof shapes vary from almost flat to
steeply pitched. They can be arched or domed; a single
Figure 4.2: Various roof shapes.
flat sheet or a complex arrangement of slopes, gables
and hips; or truncated.
Figure 4.3: Theoretical volume of rainwater collected
from a roof catchment.
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Theoretically, for every square metre of roof catchment
area, one litre of rainwater can be captured per millimetre
of rainfall (Figure 4.3). The volume of water collected is
directly proportional to the catchment area (Figure 4.3).
October 2018 Volume 24 I Number 8