What condition should timber deck areas exposed to drainage be inspected for?

Timber deck areas that are exposed to drainage should be inspected for decay because moisture accumulation is a critical factor in the deterioration of wood materials. When timber is frequently in contact with water or remains damp due to drainage, it becomes susceptible to various forms of decay, particularly from fungi that thrive in such environments.

Inspection for decay is vital, as it directly affects the structural integrity and longevity of the timber deck. If decay is present, it can compromise the load-bearing capacity of the deck and may lead to more significant issues if left unaddressed. This type of inspection helps ensure safety and informs necessary maintenance actions to preserve the bridge's functionality.

While other conditions such as warping, cracking, and fungus growth certainly can occur in timber exposed to moisture, decay is the most critical factor to identify in this context, as it is a direct consequence of prolonged exposure to water and can lead to rapid structural failure if not managed properly.