Civil Engineering Reference
In-Depth Information
30-50 cm depending upon the particular plant. The roots must have space to
grow out from the building. Certain climbing plants are sensitive to high earth
temperatures and prefer a shady root zone, which can be achieved by planting
grass or small plants over them.
Apart from hedge and hanging plants, trelliswork is needed to help the plant
on its way. Self-supporting climbers are quick to attach to walls, but others need
more permanent trelliswork. This can be a galvanized steel thin framework or
high quality timber battens. Timber battens are best placed diagonally. For fast-
growing plants and heavy masses of leaves extra watering and fertilizing will
be needed, especially at the beginning. Many of these plants must be pruned
regularly.
Indoor plants
Russian and American space scientists have been working for years with so-
called 'biological air cleaners' for use in space ships. These are plants with a high
absorption capacity for organic gaseous pollution which is normal in modern
interiors, such as vapour from solvents and formaldehyde.
Larger plants that do this are ivy (
Hedera helix
), the fig plant (
Ficus pumila
),
devil's ivy (
Scindapsus aureus
) and the tri-leaf philodendron (
Philodendron
spp.),
but potted plants such as the peace lily (
Spatiphyllum
) and the spider plant
(
Chlorophytum comosum
) also do the same. The air-cleaning properties vary
from species to species, and are also dependent upon the leaf area (see Fig.
15.15).
Timber sheet materials
Timber can be used in all the different situations where sheeting is needed: as
whole timber, as one ingredient in sheeting and as cellulose for wallpapering.
Wallpapering is discussed later in this chapter.
Timber can be used to cover roofs as shakes, shingles or planks. As cladding
it can be used as panelling or wattle, and as flooring it can be used as boards,
parquet tiles or timber sets. The sheeting is produced as fibreboard, cork, chip-
board or veneer. The first two products have their own glue in the raw materi-
al which allows them to form sheeting; the latter two need added glue. This is
usually urea formaldehyde glue added in a proportion of 2-12 per cent by
weight. Laminate products are also made with chipboard in the middle and
glued-on veneer or different types of plastic sheeting, often finished to look like
timber.
