Wet Rot
Occurs more frequently, but is less serious; decay is typically confined to the area where timber has become and remains wet. Signs of wet rot :
- Distortion, discolouration, softness and cracking
- Loss of strength to the timber
- Visible fungal growth – this may sometimes occur
- Smell – there may be a damp musty smell
Outbreaks of dry and wet rot start in similar ways. The mature fruiting bodies of wood-destroying fungi that develop during an attack produce millions of microscopic spores and these are widely dispersed by air currents. If they fall on untreated damp wood they will germinate by pushing out a hollow tube called a hypha which grows and branches to form a mass of hyphal threads called mycelium.
This develops inside the timber and breaks down the wood for food. The timber may darken in colour and develop a characteristic cracked appearance. Some wet rots may result in bleaching of the wood; these are more common in doors and window frames. Eventually, the wood loses its strength and in some situations may become dangerously unsafe.
Dry Rot
Is only caused by serpula lacrymans (see page two for more details) and is the most serious form of fungal decay in a building. It can spread onto and destroy much of the timber. Signs for dry rot:
- Distinct mushroom smell
- White fungal growth with yellow and lilac tinges
- Deep cracks appear within the wood
- Both soft and hardwoods can be damaged
What Is The Difference?
The main differences between dry rot and wet rot are the degree of development of mycelium on the wood surface and the ability of the fungus to spread into other timbers via adjacent masonry. It is important that the two types of decay be distinguished since they require different treatment.
Source:http://www.constructionchat.co.uk/
