Dry Rot

Is a wood destroying fungus causing the most serious timber decay in buildings, often resulting in extensive damage. It has the ability to grow through brickwork, mortar and behind plaster.

It can be difficult to detect in early stages as it may develop out of sight. Some indications of possible dry rot may be the softening of wood in some areas, shrinkage and distortion and a distinctive “mushroom” odour.
The timber decayed by dry rot is characteristically dull brown in colour with deep cracks across and along the grain forming cubes up to 50mm in size; similar in appearance to charred wood but not as dark. The timber becomes lightweight and will crumble. Sheets of silky, cotton wool like, white mycelium may be present. Where exposed to light these may have a lemon or lilac tinge. Strands up to 8mm thick may spread from infested timbers. These transport moisture from damp areas allowing the fungus to spread to dry wood in other areas not satisfactorily ventilated.

When conditions are suitable the fungus may form a pancake shaped fruiting body, yellow ochre with white edges when young, darkening to rust red when mature. The centre portion will then produce a mass of rust red spores, which often form a red dust cover over the surrounding area.
The destructive nature of this fungus should not be under estimated as it grows in dark, damp places, out of sight, until it produces a fruiting body which disperses millions of spores. By now, huge amounts of damage will have occurred.

The origin of the dampness must be identified and the fungus must be treated with fungicide.

The dormant fungus can survive up to ten years in damp masonry. Any rotted timber must be removed and replaced with treated timber. Insitu must be treated with fungicidal spray or timber paste or injected with fungicide pellets.

The infected masonry must also be treated with fungicidal wall solution.

Wet Rot

A general term applied to many species of fungus, all of which will cause timber decay. They can be divided into two groups; brown and white rots.

They vary in severity of damage but none possess the ability to pass through inert material to spread to other damp timbers like Dry Rot. Thus they are found localised in areas where they are exposed to considerable amounts of water ingress. Externally exposed timber, timber in contact with wet soil or masonry, or timber subject to a damp atmosphere can all suffer from Wet Rot.

Brown rots will result in the darkening of timber and cause cracking leaving cube like shapes which will also crumble. The cube like shapes are generally smaller than those associated with dry rot and therefore it is important that these characteristics alone are not relied upon for identification purposes.

White Rot may bleach the affected timbers leaving them pale in colour. The wood will develop a stringy, fibrous appearance, and although may be easily crushed, does not crumble.

Colours of associated mycelium strands and fruiting bodies will vary depending on which type of fungus causes the damage.

The remedial measures required for both brown and white rots but excluding dry rot are the same in that treatment involves eliminating the source of damp and/or perhaps replacing the timbers with brick or concrete substitue where practical. Insitu timbers maye reated with a dual purpose fungicide and insecticide for long term protection.

"Conophoria Puteana" Not to be confused with Dry Rot