Lately, it seems that there has been an epidemic of deck collapses and injuries at oceanfront rental properties. I believe that this is the direct result of inadequate inspection by the owners to identify structural deficiencies that would cause their decks to be unsafe. This is despite the fact that after a tragic Chicago porch collapse in 2003 that killed 13 and injured 55 people, yearly inspections were recommended by the International Code Council (ICC) for residential decks and balconies. This is particularly important with older beach-front decks and balconies, which were likely designed and built using galvanized fasteners and joist hangers that eventually rust when exposed to salt spray and water. As early as 2007, DCA 6 (published by the American Wood Council in cooperation with the ICC and Fairfax County, Va.) recommended the use of stainless-steel bolts, lag screws, joist hangers, and nails for decks or balconies that are exposed to salt water or located within 300 feet of the ocean, to prevent salt corrosion.
Another potential structural problem is the deck ledger connection to the house. While current model building codes require the deck ledger to be fastened to the structure with either 1/2-inch bolts or lag screws, in the past nails were often used, resulting in a countless number of decks that are potentially unsafe. Inspection by a qualified professional should uncover structural deficiencies in the ledger that would require immediate repairs or even a deck replacement.
Guardrails should also be regularly inspected. The current residential code does not prescribe how guard posts should be attached to the deck structure, and many residential contractors—and DIYers—who build decks aren’t familiar with the DCA 6 (awc.org/publications/DCA/DCA6/DCA6-12.pdf), which does contain a recommended detail for connecting guardrail posts to a deck. As a result, many deck guards that get built have not been load-tested (based on code-prescribed loads), and some may be structurally unsafe.
Ideally, inspections would be conducted by a registered design professional (RDP), typically a registered engineer who has knowledge and experience in inspecting wooden decks and balconies. The property owner’s or the property manager’s main objective for a deck or balcony safety inspection should be to determine whether the structure is safe based on the most current code for the location, coupled with industry recommendations for a safe deck and guardrail system. They should be very clear in their request for an inspection: Is the deck or balcony unequivocally safe in its current condition for future use? If not, the deck should be tagged as unsafe, not occupied, and immediately removed or replaced.
Frank Woeste Professor (Retired)
Virginia Tech University
Blacksburg, Va.