London Bridge isn’t the only thing falling down!

A special guest blog post from Don Carter PE a structural engineer I have enjoyed working with over the years. Not only do I respect him and value his wisdom he is a wonderful family man also! I will never forget one morning many years ago when I stopped by to drop off project drawings and he met me at my mom van to save me from unbuckling my new-born son’s car seat and jostling him awake. My first words were to explain a point on the project he interrupted… ”the project can wait let me see your baby”.  Thank you Don for always keep it straight family is first

This post reminds us in addition to creating a beautiful space that meets needs,  above all it has to be safe for your family. Hire a professional engineer. Don Carter PE can be reached at Foundation Engineering Specialists LLC WWW.fdnengineering.com (913)685-1434

Deck failure. Use a professional structural engineer to keep your family safe. Photo courtsey of Simpson Strong Tie.

A colleague recently shared that when his lake home’s deck began to show signs of rot on the walking surface he took up the damaged boards, only to discover that the main structure underneath was also rotting — but to a much greater degree.  Out of sight out of mind.   Our company looks at maybe half a dozen balconies, porches or decks each year that are in some stage of noteworthy failure, and it’s a growing part of our business.  With the average life expectancy of a wood deck being 10 to 15 years nationally, maybe a little more in Kansas, this problem will increase as Johnson County subdivisions age.  Decks cause more injuries and loss of life than any other part of the home structure.   Since 1999 there have been 850 reported injuries and 20 deaths as a result of deck failures1.  We see 3 reasons for this:

  1. Under Design.  Many decks and porches are added by homeowners as a weekend project. Without a credible plan, these decks are often built based on what looks nice, not what meets the requirements of elementary engineering. Local cities have rigid rules to control deck construction, but their inspectors can’t be everywhere so accessory structures are often built without plan review, permitting or final certification. 
  2.  Materials Breakdown.  These are outdoor structures subject to all the ravages of Midwestern weather. Without periodic maintenance, Mother Nature easily has her way with exposed wood.  Years ago redwood was the deck builder’s material of choice because it looked nice and seemingly lasted forever.  But when cost and availability changed, redwood gave way to cedar which in turn gave way to treated fir.  Early wood treating chemicals protected wood for a long time but they contained arsenic and are now banned.  The jury is still out on how long newer chemical treatments will last, but no material can sit outside and retain its original properties forever.
  3. Unplanned Loads.  Decks and balconies are code specified for people and light accessory loading, same as inside living space. It’s not uncommon though to see people adding a hot tub at more than triple the per square foot loading.  What started out as a capable structure gets increased loading with no thought given to reassessing the frame or foundation.  I recently examined a failed second story balcony, which was debris on the lawn by the time I saw it.  Eyewitnesses reported that the balcony had been loaded with people standing shoulder to shoulder and still others sitting on the hand rails.  After a lot of lawyering, the building owner was held liable because he hadn’t posted a load limit.  I doubt the average homeowner has any earthly idea what his deck’s occupancy limit should be.

For your liability protection and the safety of family, guests and self, make time to look at your deck with a critical eye.

1.Photo and select information for this article were obtained from Simpson Strong Tie

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