TAFE wet area text.pdf - Mike's Trade Wiki

WET AREA CONSTRUCTION
Water Damage, Decay and Fungal Growth
Water damage may occur due to poor flashing practices, poor ventilation or using materials,
which don’t provide adequate resistance to water penetration.
The result of this water penetration may be:
� Timber decay in wall framing;
� Timber decay in floor framing;
� Fungal damage to surrounding materials;
� Swelling of manufactured boards such as particleboard;
� Musty odours from enclosed spaces;
� Damage or staining to fitments.
Fungal Growth
Timber decay is caused by fungal growth feeding on the lignin and cellulose, which makes up
the bulk of the timber’s structure.
To exist the fungi will require suitable conditions, as follows:
� A food source, such as timber;
� Water or a high moisture content, i.e. above 18%; and
� Oxygen.
The fungi, unlike plant forms, does not need light to exist therefore, dark moist places are very
suitable for it’s existence.
Fungi produce fruiting bodies, which develop spores. These spores are dispersed and become
new fungal growths having an appearance like a surface root system, known as mycelium.
Most fungi or ‘rot’ require high levels of moisture, at least 18% to start, however there is one
species, Sepula lacrymans (commonly caled ‘Dry rot fungi’), which requires only humid
conditions to survive.
(refer to Building Materials and Hand Tools for more details relating to Fungi)
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Fig. 38 Typical result of leakage from a poorly flashed fitment
©TAFE NSW Construction and Transport Division