Timber decay happens when certain species of fungi attack the insides of the wood.
The fungus can lie dormant within the timber for years and becomes active when the right conditions present themselves. Timber decay fungi can destroy the structure of any building if left untreated. Since timber decay fungi live inside the wood, there’s really no way you can identify them early on. Usually, the only time you’ll probably suspect of any infestation is when you notice some structural weaknesses in your home, such as weakened floorboards, corrupted floors, and damaged windowsills. Fungal infestation treatment is a bit technical and should be handled by professionals.