Timber Decay
Timber has a very good strength to weight ratio which makes it a valuable building material.
In the right conditions, and if properly treated, some seasoned hardwoods are remarkably durable. However, over time the treatments will deteriorate and, where the timber is used in vulnerable and potentially damp locations, such as wall plates or ground floor joists bedded into walls it will be susceptible to fungal decay.
Chartered Surveyors who suspect fungal decay sometimes defer the matter to a ‘specialist’ timber and damp-proof company. The competent surveyor should, however, be expected to identify the type of fungus causing decay, make a reasonable assessment of the likely extent of infestation, and provide advice on remedial works.
Dry Rot (Surpula Lacrymans)
Dry Rot is described in the Bible as ‘Leprosy of house’:
“if the plague be in the walls of the house with hollow strakes, greenish or reddish, which inside are lower than the wall; Then the priest shall go out of the house to the door of the house, and shut up the house seven days: And the priest shall come again the seventh day, and look: and, behold, if the plague be spread in the walls of the house; Then the priest shall command that they take away the stones in which the plague is, and they shall cast them into an unclean place without the city;”
(Leviticus 14: verses 37-40)
It is one of the more damaging types of fungus but, fortunately, is also one of the more easily identifiable. Some of the main characteristics of Dry Rot have been set out below:
Dry Rot is well known and feared for its ability to quickly propagate throughout a property, even penetrating areas where moisture content is low. It achieves this by sending out feeder strands for several feet (even through brickwork and plaster) to find a source of moisture and nutrients which is sent back to the growing area.
It is these feeding strands that tend to be concealed within voids or behind masonry and plaster work that make Dry Rot difficult to eradicate. The strands are also the reason for the Latin name ‘Surpula’ meaning ‘a little snake’
Dry Rot causes deep cuboidal cross-section cracking to the affected timbers and a darkening to the colour of the wood. It has a cotton wool type growth with a slightly yellow tinge to the edges. The fruiting body (sporophore) appears as an impressive corrugated fleshy cap, initially of a light grey colour tinged with yellow but gradually turning a deep red rust as the spores develop.
Once the main fruiting body is ready to eject its spores, they are discharged at a rate of up to 800 million every day – over a period of around two weeks. This discharge of spores usually results in a fine orange dusting to nearby surfaces. In the right conditions these spores germinate and grow into hyphae which resemble fine stringy cobwebs. The hyphae penetrate and feed on the timber. They then begin to multiply and colonise into a large mass known as mycelium which has the appearance of fluffy cotton wool. It is the mycelium strands which are sent out through brickwork and other non-organic materials to find sources of additional moisture and nutrients which enable the final stage of growth into the fruiting body and the cycle repeats.
David Cosby Chartered Surveyors and Estate Agents have the benefit of a combined 40 years Surveying and Legal expertise. We believe that it is our knowledge and professionalism that helps to sell homes. As one of our clients articulately put it “No gimmicks, no annoying sales people – just professionals who make it look easy!”
If you are purchasing a property and need a survey or if you are thinking of selling and would like a market appraisal, please call us on 01327 361664 or click the link below.
