Dry Rot Fungus
Dry rot is caused by a fungus and is the most damaging destroyer of wood construction materials in temperate regions. The geographical source of spread and colonization by this fungus in human environments is somewhat of an enigma.
According to the National Institutes of Health, dry rot fungus is divided into two main lineages: one nonaggressive, residing naturally in North America and Asia, and another aggressive lineage, including specimens from all continents, both from natural environments and buildings.
According to the National Institutes of Health, dry rot fungus is divided into two main lineages: one nonaggressive, residing naturally in North America and Asia, and another aggressive lineage, including specimens from all continents, both from natural environments and buildings.
Genetic analyses indicate that the two lineages represent well-differentiated species and pinpoint mainland Asia as the origin of the aggressive form var. lacrymans. A few aggressive genotypes have migrated worldwide from Asia to Europe, North and South America, and Oceania, followed by local population expansions.
Studies indicate that they have established through recent migration events, for example, by infected wood materials transported over land or sea. A separate colonization has happened from mainland Asia to Japan.
This information is courtesy of the following National Institutes of Health publication: Asian origin and rapid global spread of the destructive dry rot fungus Serpula lacrymans.
Dry rot spores are everywhere in the atmosphere, and if the condition of the timber becomes suitable, it is likely that the spores will germinate and result in an outbreak of decay. The main requirement is that the timber moisture content is in excess of 20%. This is not a very high level, given that "dry air" timber has a moisture content of 12-16%.
Certain timbers are resistant to fungal attack, even when very damp, but these are not generally used in house construction. A large fruiting body of the fungus can produce 800 - 900 million spores per hour. In ideal conditions, its growth is very rapid, and will soon cause the timber to become cracked both with and across the grain.
Serpula lacrymans (Dry Rot) prefers dark conditions, inadequately ventilated places, and often remains undetected until severe damage has been caused. Often, the first knowledge the householder has of its presence is the cracking and/or buckling of skirting boards or rust brown spore dust. It is capable of spreading behind plaster, through mortar joints, and even across metal to find more timber or moisture to feed on. i.e., a non-nutrient medium.
Studies indicate that they have established through recent migration events, for example, by infected wood materials transported over land or sea. A separate colonization has happened from mainland Asia to Japan.
This information is courtesy of the following National Institutes of Health publication: Asian origin and rapid global spread of the destructive dry rot fungus Serpula lacrymans.
Dry rot spores are everywhere in the atmosphere, and if the condition of the timber becomes suitable, it is likely that the spores will germinate and result in an outbreak of decay. The main requirement is that the timber moisture content is in excess of 20%. This is not a very high level, given that "dry air" timber has a moisture content of 12-16%.
Certain timbers are resistant to fungal attack, even when very damp, but these are not generally used in house construction. A large fruiting body of the fungus can produce 800 - 900 million spores per hour. In ideal conditions, its growth is very rapid, and will soon cause the timber to become cracked both with and across the grain.
Serpula lacrymans (Dry Rot) prefers dark conditions, inadequately ventilated places, and often remains undetected until severe damage has been caused. Often, the first knowledge the householder has of its presence is the cracking and/or buckling of skirting boards or rust brown spore dust. It is capable of spreading behind plaster, through mortar joints, and even across metal to find more timber or moisture to feed on. i.e., a non-nutrient medium.
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