Civil Engineering Reference
In-Depth Information
Wall cladding with plants
The qualities achieved by cladding walls with plants are somewhat similar to
those of a turf roof, with increased wind and rain protection, extra thermal insu-
lation and sound insulation, and better air quality.
There is a certain amount of scepticism as far as plant-clad walls are con-
cerned, based on two main points: that the plants, especially ivy, eat into the
wall, and that leaves can house all sorts of insects which can get into the build-
ing. However, as long as the materials used in the building are mineral, such as
brick, and the render is of a high quality, then no damage will be caused by
plants. In fact, they have the complete opposite effect, protecting the render
from driving rain, drying out and large fluctuations in temperature. In
Germany, rendered walls like these have lasted up to 100 years, while normal
buildings have been re-rendered three to four times during the same period
(Doernach, 1981).
Walls clad in timber panelling and other organic materials are less suitable for
plants, but if they are planted, there must be plenty of ventilation between the
plant and the wall. Ivy and other climbers that extend their roots into the wall
should not be used.
Problems with insects have proved to be almost non-existent.
Climbing plants need no particular source of energy except a little fertiliz-
er; the sun does the rest. The life span of these planted surfaces can be as
much as 100 years, and ivy has been known to grow on a building for 300
years.
Orientation and planting
The different façades of a building offer different growing conditions for
plants, just as plants can have different uses on different façades depending
upon their orientation. On the south side plants that lose their leaves during
winter should be grown to take advantage of solar radiation during the win-
ter. In milder climates, fruit or vegetables such as grapes or tomatoes can be
grown. On the east or west side it is better to have evergreens that form a
thick green layer. Deciduous plants can be used if they have a dense growth
of branches or have a hedge formation. On the north side it is necessary to
find a thick layer of evergreen vegetation that is not dependent upon sun-
shine.
The planting has to be done during the spring or the autumn. The plants can
be bought at a garden centre or found in the forest (e.g. honeysuckle, ivy, hops
and blackberries). The plants are placed in the earth at 30-50 cm spacing and
about 15 cm out from the wall. The depth of the holes should be between
