What is the most common cause of deck collapse?

The most common cause of deck collapse is due to ledgers that pull away from the band joists. The ledger board is a critical component of a deck's structural support, as it attaches the deck to the house. If the ledger is not properly secured or if it becomes compromised through decay, moisture, or improper installation, it can detach from the band joist. This detachment can lead to a failure in supporting the deck, often resulting in a sudden and dangerous collapse.

Moreover, the functionality of the ledger board directly affects the integrity of the entire deck structure. When a ledger board pulls away, the load that it is supposed to carry may shift, leading to excessive stress on other components of the deck, which can cause further structural failure. This scenario highlights the importance of proper installation and maintenance of the ledger board to ensure the overall safety and stability of the deck.

Understanding this risk is crucial for both home inspectors and homeowners, as regular inspection and correct fastening techniques can prevent such catastrophic failures.