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, 850 injuries and 20 deaths have been reported as a result of deck failure.*

We see three reasons for this:

1. Under-design. Many decks and porches are added by homeowners as a weekend project. Without a credible plan, these decks often are 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 often are built without plan review, permitting, or final certification.
2. Materials breakdown. These outdoor structures are 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 the chemicals 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, the 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 that 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 or her 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. The next Home Front column will feature five check points to help give your deck or balcony a physical exam.

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