by Androniki Bossonis


While global outpourings of sympathy resonate for the victims of Monday’s balcony collapse in Berkeley, CA, the overriding questions are, how did this happen, and could it have been prevented?

Gene St. Onge, a veteran civil structural engineer, spoke out on Tuesday that clearly, the deck failure was caused by dry rot resulting from water intrusion. While the building’s balconies were designed to support the weight required by code, there were apparently no door pans installed, and there may have been additional sources of water intrusion.

Water intrusion and dry rotted wood don’t just suddenly cause a deck to snap; there are clear signs of leaks and rot that would have been immediately obvious to a qualified deck inspector. Waterproofing system manufacturer’s recommend a balcony deck inspection every 3 years, to catch small repairs that may lead to structural damage or deck failure. The Berkeley deck that failed was only 8 years old, but an inspection at the 3 or 5 year mark could have prevented the tragic balcony collapse.

When you have a plumbing leak in your home, it’s a mess, and some of your personal property may get ruined. But when you have a leak in a waterproof deck, the result can range from expensive structural damage to fatal deck collapse. Despite the severity of the potential consequences, many homeowners or property managers do not see the need for regular deck inspections and maintenance, because the decks often look fine on the surface. They don’t realize the water is penetrating beneath the surface, where the damage is compounding, invisible to the untrained eye.

Dry rot was also the cause of the deck collapse in San Francisco in 1996, which resulted in 14 injuries and one death.