Control of Dry Rot Fungus, Serpula lacrymans

Conventional methods for eradicating dry rot are often drastic, involving the removal of infested wood and application of biocides to prevent re-infestation (see Dry Rot Fungus References). Popular beliefs are that eradication of dry rot is almost impossible and that the fungus is particularly resistant to treatment. These beliefs are misleading and arise mainly from the fact that Serpula lacrymans can survive for extended time periods in masonry and it can transport water and nutrients over long distances. So, simple drying of localized infested wood may be insufficient to achieve eradication of the fungus. Because of these abilities, there is no doubt that control of Serpula lacrymans can be a challenge, but this may easily be overcomed by removing moisture from the entire environment in which the fungus is growing.

There are two principles for the control and eradication of dry rot fungus- the primary and secondary measures.

Primary Control Measures For Dry Rot Fungus, Serpula lacrymans

As with most indoor fungi, the most vulnerable feature of Serpula lacrymans is its requirement for water. Control and elimination of water forms the primary measure for the control and elimination of dry rot fungus. The primary measures involve:

• Locating and rectify the source of water causing and maintaining dry rot fungus.
• Promoting and maintaining rapid drying conditions in the affected building.
  The elimination of the source of water and rapid drying is the first point of attack. It is absolutely necessary to stop further water intrusion into the building. This action alone will eventually control and eliminate the growth of dry rot fungus. Depending on the extent of damage, secondary measures may be required.

Secondary Control Measures For Dry Rot Fungus, Serpula lacrymans

Secondary measures are important where the damage has been extensive. After the primary measures, take the the following secondary measures

• Remove and destroy all or portions of infested wood. The removal of the food source will generaly quickly stop the spread of growth of the fungus.
• Replace removed wood with pre-treated wood (double vacuum/pressure impregnated as appropriate) or inert materials such as concrete, steel, etc. Give consideration to the use of preservatives for steeping joist ends prior to reinstatement.
• Spatially and physically isolate the dry rot fungus. Reinstate wood using joist hangers, joinery wrap. These deny the fungus a potential food source and they also prevent the wood from becoming wet.

It is essential that the primary measures are taken immediately before deciding on the secondary and supportive chemical treatments. All risks should be thoroughly evaluated where wood is likely to remain embedded or in damp conditions, even where treated, and it is essential that in such cases the centre of the wood receives full treatment.