Fungal Decay of Timber
Timber in contact with damp masonry is at risk of fungal decay and insect attack.
20 per cent moisture content of timber is sufficient for dry rot (serpula lacrymans) spores to germinate.
Dry rot prefers hidden environments away from air currents thus the presence of timber, moisture and lack of ventilation are 3 key ingredients in its germination.
As its origin is likely to be hidden in concealed areas considerable fungal growth can occur prior to it being discovered. Rate of growth can be 1000 mm per month but the area of growth can be in all radial directions thus a metre of growth could occur in a month.
It is essential to identify the source of moisture which triggered the outbreak. Reinstatement while not rectifying the cause is not effective in the long term
Growth can occur through party walls and liability can rest upon the owner whose house is the site of the cause of the outbreak.
Wet rot coniophera puteana occurs when moisture content of timber is higher than 20 per cent.
The ISSE Home Log contains a detailed summary of fungal decay. Please consult that section.