FUNGAL DECAY IN TIMBER

The reproductive spores of a mould fungus and the vegetative threads (mycelium) of a wood decay fungus, the latter usually white, if present in sufficient quantities, can be seen with the naked eye.  However, vegetative growths of wood decay fungi may be cream, brown or black. 

Wood Decay fungi prefer to grow where conditions of temperature and moisture content are not subject to fluctuation.  For timber out of ground contact, such a stable situation is more often deep in the wood than on the surface.  When the fungus has exhausted the available nutrient from the timber, new growth is supported by feeding on the older growth and so the fungus may grow on other surfaces away from the timber leaving very little visible evidence of fungal growth on the wood itself.  Soft rot fungus for example.

In general, decay of floorboards is caused by brown rot fungi, decay of window joinery by either brown rot or white rot fungi and decay of weatherboards often by white rot but sometimes by brown rot fungi.  House stumps and fence posts decay from soft rot but may also have either brown or white rot.  Serpula lacrymans (formerly Merulius lacrymans) is the world's most destructive fungal decayer of timber in buildings.  This brown rot fungus has an optimum temperature for growth at 20 degrees C (c.f. most wood decay fungi 25-28 degrees C).  Consequently, this fungus causes widespread damage in poorly ventilated subfloor areas in buildings around Asutralia where subfloor areas may be protected from the extremes of external temperatures.  Probably as a result of high external temperatures, a species of Coniophora (also causing brown rot) is believed to be the commonest house timber decay fungus in Australia. 

Appearance of decay of timber

Decaying wood and decayed wood are visually quite different.  Decaying wood contains sufficient moisture to retain its original shape and may have sufficient strength to withstand normal loads. 

In contrast decayed wood is reduced both in moisture content and size as indicated by cracking either along or across the grain or by fibres coming apart in a stringy manner.  Decayed wood will have undergone considerable strength reduction and in the case of floorboards could be eventually expected to fail under the load of humans or furniture.

Call BITE BACK PEST CONTROL TODAY! and we will conduct a full visual timber inspection for your home. We will test the moisture content of the timber  in all areas perceived to be damp or where ventilation is considered to be inadequate.