Fungal decay


Fungal decay

Wet Rot
The most frequent cause of damage to timbers in a building is fungal decay. There are many forms of fungal decay affecting timbers in properties, the majority coming under the heading of wet rots; the most common being Coniophora puteana (Cellar Fungus). Normally the cause of both Wet and Dry Rots is high moisture content in the timbers coupled with poor ventilation. However, Wet Rot does not have the ability to spread its attack in the way that Dry Rot will, and is limited to the areas that contain a sufficiently high moisture content to support fungal growth. Outbreaks of Dry Rot and Wet Rot start in similar ways. Initially, microscopic airborne spores (emanating from mature fruiting bodies) can settle on damp timbers, instigating the wood destroying cycle. The areas most commonly affected by decay are suspended timber ground floors and associated joinery, where inadequate ventilation and structural defects have allowed timbers to absorb moisture. If not treated, such decay can result in the structural weakening and failure of the affected timbers. If the fabric of the building has not been maintained in a dry and weatherproof condition, and water penetration occurs, fungal decay can affect other joinery and structural timbers in the building.

Treatment
Fungal decay by wet rots can be arrested quickly when the moisture source is eradicated, allowing treatment and repairs to be carried out. Once the type of decay has been identified by our experienced surveyor, a detailed report and estimate will be submitted for chemical treatment and repairs to the affected timbers. A 20 year guarantee will normally be issued in respect of the treatment carried out.

Dry Rot
The True Dry Rot Fungus (Serpula lacrymans), literally translated as Weeping Fungus, is a particularly sophisticated and dangerous type of fungi. It has unusually thick fungal strands (mycelium) which conduct moisture and nutrients; feeding growth which can lead to the formation of fruiting-bodies.

It should be noted, therefore, that outbreaks of the True Dry Rot Fungus are far more serious and difficult to eradicate than any other wood destroying fungus. This is due to a combination of factors.

1. Due to the conducting strands; it can spread very rapidly to suitable nearby wood, across non-nutrient material such as concrete, brick, plaster and stonework.
2. The Dry Rot fungus will attack wood, which is less damp than necessary for other types of fungi.
3. Destruction of attacked wood is very rapid.
4. Dormant strands in damp walls etc. make eradication more difficult. Unless thorough opening up works are carried out, there is always the risk of a renewed outbreak occurring.

The appearance of a “fruiting body” may be the first indication of a Dry Rot outbreak, and it is important for an experienced surveyor to carry out a detailed inspection in order to identify the type of fungi present and the source of moisture. Very often intermittent leaks cause the problem, the lower levels of moisture, as suggested in the name “dry” rot, enable Serpula Lacrymans to flourish

Treatment
Once the moisture source has been stabilised, suitable repairs must be carried out to prevent further moisture ingress. The whole area affected by the decay requires to be ‘opened up’, and a detailed specification will be provided by our experienced surveyor for the preliminary opening up works, in order to establish the extent of the outbreak. This will entail removing timbers, wall plaster, joinery etc. beyond the last visible signs. If the outbreak is found to be contained within the initial area found, a detailed specification and estimate will be provided for the necessary remedial treatment, sterilisation and reinstatement works.