The attacks of insects are stimulated by former wood degradations by fungi.
Fungi attack wood when the following conditions are met:
The water content of wood is measured using an electrode hygrometer. This rate varies according to the water content of air and to ambient temperature but can exceed 20% when the wood is put in direct contact with liquid water (leak, condensation...).
A wood of interior is therefore not attacked by fungi unless it is placed under abnormal conditions of use.
The spores of fungi being omnipresent in the atmosphere, the attack is
inescapable as soon as the conditions of temperature and moisture are met.
The development of fungi inside wood starts with the germination of the spores, which generate filaments of mycelium. In the presence of light, the mycelium can generate external fructifications, which will emit in their turn spores in the atmosphere, increasing the degradation of wood.
The dry rot fungus (Serpula lacrymans) destroy cellulose and gives to wood an aspect fissured in 3 directions (cubic rot).
The dry rot fungus is responsible for approximately 70% of the fungi attacks in Northern Europe. It attacks wood (preferably softwood) as soon as its water content exceeds 22%.