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.
