At what moisture percentage does active decay of wood begin?

Active decay of wood typically begins when the moisture content reaches approximately 28%. This level of moisture creates a suitable environment for wood-destroying fungi to thrive, resulting in the breakdown of cellulose and lignin in the wood structure. When moisture content exceeds this threshold, it increases the likelihood of fungal growth, leading to the deterioration of the wood.

In contexts such as pest control and structural integrity, understanding this moisture level is crucial. It emphasizes the importance of keeping wood and wooden structures dry and well-ventilated to prevent decay and the associated issues, including pest infestations. Other options, while close, fall below this critical threshold where significant decay processes start, underscoring the importance of maintaining moisture levels below 28% to protect wooden materials.