What is a frequent cause of catastrophic deck collapse?

A frequent cause of catastrophic deck collapse is indeed the deck ledger pulling away from the house. The ledger board serves as the critical connection point between the deck and the home's structure. It is typically bolted or lag-screwed to the house, providing support for the weight of the deck itself and any additional loads, such as people, furniture, or environmental factors like snow.

If the ledger is improperly installed, deteriorated, or not securely fastened due to corrosion or damage over time, it can lose its anchoring capability. This can lead to structural failure, particularly when weight is added to the deck, causing an abrupt and dangerous collapse.

The risk associated with the ledger board is compounded by potential issues like moisture intrusion that could lead to wood rot or pest infestation, further weakening the connection. Regular inspections and proper installation techniques are crucial to ensuring that the ledger remains secure and capable of supporting the deck.

While other factors such as improperly installed railings, heavy furniture, and incorrectly placed deck supports can contribute to lesser structural issues, they are generally not the primary cause of catastrophic failures compared to a compromised ledger connection. Proper attention to the ledger’s integrity is therefore essential for deck safety.