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Timber Treatments
Importance of Identification
Not all fungi found
in buildings cause wood rot. However,
the presence of any fungal growths
indicate that damp conditions exist
which are also suitable for the development
of wood rotting species and some remedial
measure may be necessary to remove
the source of dampness.
Types of Wood Rotting
Fungi
There are two main
types of wood rotting fungi found
in buildings
Dry Rot "Serpula Lacrymans"
General: Mostly
Softwoods
Major building decay fungus often
causing extensive damage. A brown
rot, which typically occurs on wood,
embedded in, or in contact with wet
brickwork. Sensitive to height temperatures
(over 25c) and drying and therefore
rarely found on exposed timbers or
situations where fluctuating conditions
are likely, e.g. well ventilated sub-floors
and roofing timbers. It is able to
grow through bricks and mortar, though
cannot feed on these. Strands can
transport moisture from damp areas,
allowing spread of the fungus to dry
woo in unventilated conditions. Appearance
of fruit-body may be the first indication
of an outbreak.
Checking for moisture
in timber is vitally important to
protect against or find fungal decay
and beetle attack
Damage Characteristics
Decayed wood, dull
brown in colour. Deep cracks along
and across the grain, light in weight
and crumbles between the fingers,
these are all typical features. No
skin of sound wood.
Fungal Characteristics:
"Mycelium"
Silky white sheets
or cotton wool like white cushions
with patches of lemon yellow or lilac
tinges where exposed to light. In
less humid conditions forms thin,
felted grey skin. During active growth
the advancing hyphal edge forms a
silky fringe.
"Strands"
White to grey, branching,
sometimes as thick as a pencil, brittle
when dry.
"Fruit-Body"
Usually on wood/wall
joint, rare on exterior of building.
Tough, fleshy, pancake or bracket
shaped. Centre is yellow-ochre when
young, darkening to rusty red when
mature owing to spore production,
covered with shallow pores or folds;
margin white or grey. |
