There have been so many deck collapses throughout the country over the years that just a couple of years back the IRC (code governing residential construction) was amended to include prescriptive methods for deck attachment and bracing.
Too many decks are poorly attached to the house, some with ledger board simply nailed into the sill. Code now calls for attachment with lag screws of a certain size or through-bolted to the rim board, and with a certain maximum spacing. Code now also calls for inclusion of at least two devices to provide transfer of lateral loading to the interior floor structure. Unfortunately, most towns haven't adopted the most recent version of the IRC, but still go by 2006 or 2009.
Even if the deck structure has sound construction, too many haven't been flashed properly against intrusion of rainwater at the point of attachment to the house, resulting in sill rot over the years. Still others lack proper lateral bracing to keep the deck surface from swaying under heavy load.
News like this should be a wakeup call to everyone with a deck. Inspect it regularly.
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