Deck safety is something most people take for granted. We buy a home with a deck; as long as it is beautiful, we are not concerned about safety. There are many sobering articles on deck failures in the US that we need to take seriously on the internet. But the reality of it what we see is just the tip of the iceberg. Many components make a deck, and if any of these components fail, the deck will fail. The tragedy about deck failure is it will collapse with someone standing on the deck while enjoying themselves.
This blog is about deck safety and what you need to know about the deck components.
Because decks appear to be simple to build, many people do not realize that decks are, in fact, structures that need to be designed to resist certain stresses adequately. Like any other house or building, a deck must be designed to support people’s weight, snow loads, and objects. A deck must be able to resist lateral and uplift loads that can act on the deck due to wind or seismic activity. Deck stairs must be safe and handrails graspable. And, finally, deck rails should be safe for children by having proper infill spacing. A deck failure is any failure of a deck that could lead to injury, including rail failure or total deck collapse. There is no international system that tracks deck failures, and each is treated as an isolated event rather than a systemic problem. Very few municipalities perform investigations into the cause of the failure, and the media are generally more concerned with injuries rather than with the causes of collapses. Rail failure occurs much more frequently than total deck collapses; however, because rail failures are less dramatic than total collapses and normally don’t result in death, injuries from rail failures are rarely reported. Here are some interesting facts about deck failure:
- More decks collapse in the summer than during the rest of the year combined.
- Almost every deck collapse occurred while the decks were occupied or under a heavy snow load.
- There is no correlation between deck failure and whether the deck was built with or without a building permit.
- There is no correlation between deck failure and whether a homeowner or a professional contractor built the deck.
- There is a slight correlation between deck failure and the age of the deck.
- About 90% of deck collapses occurred due to the separation of the house and the deck ledger board, allowing the deck to swing away from the house. It is sporadic for deck floor joists to break mid-span.
- Many more injuries are the result of rail failure rather than complete deck collapse.
- Deck stairs are notorious for lacking graspable handrails.
- Many do-it-yourself homeowners, and even contractors, don’t believe that rail infill spacing codes apply to decks.