At what percentage of moisture content can wood rot occur?

Wood rot typically occurs when the moisture content of wood exceeds 20%. At this level, the conditions become favorable for decay fungi to thrive, which lead to the breakdown of the wood tissue. Moisture content above this threshold creates an environment where microorganisms, particularly wood-decaying fungi, can metabolize the cellulose and lignin in wood, resulting in structural damage.

While lower moisture content can lead to wood damage or attract pests, it is generally understood in the field of microbial remediation that the risk of rot substantially increases at and beyond the 20% moisture content mark. Therefore, this threshold is critical for professionals assessing the risk of wood rot in affected areas and devising appropriate remediation strategies.