This is the first of what we hope will be many posts to the new Blog here at Nolan Engineering. Periodically we hope to bring you interesting articles about building, design, architecture, code issues, and maybe even a bit of fear-mongering (did I just say that?).
And speaking of fear-mongering, our first series of articles will be about deck safety and some ideas on how to check your existing deck and determine if it needs attention or an inspection. We will also discuss what the code says we need, and how we can achieve these requirements.
Now for the Fear-mongering! First up is an oft-quoted study that looked at statistics involving deck related injuries from 2003-2007. While this study is sometimes criticized as being vague and misleading, its findings were an eyeopener for me. During that 5-year period there were 224,740 injuries from a deck or wooden porch. 33,270 of those were the result of structural failure of collapse.
If that doesn’t do it, according to NADRA (the National Deck and Railing Association), there are over 40 million decks in the US that are over 20 years old. Codes were different when these decks were built, so any deck that old needs to be inspected. Here is a link to download a copy of the NADRA Deck evaluation Checklist which will give you an overview. However, if you’re not sure and want a professional opinion, Nolan Engineering offers certified and licensed inspection services, as well as engineering services to help you with your design if you decide to rebuild or repair.
A few more facts??
According to the International Association of Certified Home Inspectors (InterNACHI):
- More than two million decks are built and replaced each year in North America.
- InterNACHI estimates that of the 45 million existing decks, only 40% are completely safe.
- 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.
- Almost every deck collapse occurred while the decks were occupied or under a heavy snow load.
- About 90% of deck collapses occurred as a result of the separation of the house and the deck ledger board, allowing the deck to swing away from the house. It is very rare for deck floor joists to break mid-span.
- Many more injuries are the result of rail failure, rather than complete deck collapse.
In the next few articles, we will cover some of the Code requirements, how best to meet those requirements, and some recommendations that may go beyond the code but make sense. Upcoming topics include:
- Railing, design loads and railing attachments
- How the ledger attaches to the house
- Foundations and the posts connection to both the deck and the foundation.
We hope these articles will inform and help you, whether you own a deck or perhaps are planning to build one yourself. Remember, if you’re not sure about something and think a professional inspection is needed, or are interested in design and/or engineering services for your deck, we here at Nolan Engineering are ready to help.