KoatchimieKoatchimie

 la protection du bois depuis plus de 35 ans

Rot fungi

Many different species of fungi may cause decay of structural timbers and other construction woods. Wood destroying fungi will generate so-called "rots". These rots will be classified according to the type of fungi : mould fungi, soft rot fungi. Keep in mind that fungal growth requires high level of moisture in a confined space.

Dry rot

Most known and most widespread is dry rot or Serpula Lacrymans ; this wood destroying basidiomycete fungus can start its action as soon as moisture exceeds 20 - 22 %.

Dry rot needs moisture and also other physical factors may help it develop (i.e. confined spaces, lack of ventilation...). Temperature plays an important role : below 18 - 20 °C or above 30 °C, dry rot exhibits a slower life cycle.

When the above conditions are met, filaments will start growing from the spores and will extend themselves to the whole wooden parts to form the mycelium. On the surface, dry rot will form a cotton-like material and other filaments calles "syrrotes" will search for water through the joints of masonry. Dry rot can develop on various wood species and, in particular, on softwood. Degraded woods will then become brittle and dry.

Dry rot may be confused with brown cellar rot ; however, this one will attack woods with higher moisture levels (at least 40%). Because of this specific requirement in moisture, brown cellar rot is less widespread. Woods which have been degraded by brown cellar rot will end into small fibers and turn to a very clear colour.

Many other wood destroying fungi species may be encountered but all of them will require very high moisture levels (higher than 50%) and will give the woods a spongy appearance.
 

Curative treatment against fungi

Each case requires a specific treatment.
However, these treatments are complex and only skilled professionals should be contracted.

 

WORKS :

2 types of curative actions must be carried out :

  • restoring a healthy and a clean state of the building including an effective ventilation.
  • remedial treatment against fungus.
     

PREPARATORY STAGE

Floors and walls (masonry) :

  • remove coatings and expose bare surfaces to treatment.
  • flaming and brushing of the masonry to eliminate any source of nutriment for the fungi.
  • removal and disposal of rubble and waste according to local laws and regulations.

Timbers and other wooden parts :

  • checking and appropriate chopping of the timbers/woods to be kept.

Curative treament of walls and floors

Against dry rot :

  • injection of Koatmerule into the infested area and also one meter around it.
  • spraying onto the whole infested surface.

Against any other fungus :

  • spraying onto the whole infested surface.

Treatment of timbers and wooden parts to be kept :

  • injection of Koatmerule into the infested area and also one meter around it,
  • double injection into embedded timbers with eventually if the cross section allows it, a complete through injection,
  • spraying onto the whole infested surface.