Balcony & Deck Collapses
The recent deadly balcony collapse in Berkeley, California has caused some to ask if this could happen to them? Balcony and deck collapses are not typical, but it does seem like we hear about these incidents frequently. To allay your fears, first keep in mind the Building Code prescribes loads to the structural engineer that result in the design of a safe balcony. This required live load is in the 40 to as much as 100 pounds per square foot range depending on the application. So even if the lowest load rating is used, a properly design deck will support the weight of a 160 pound person occupying every two foot by two foot square area on the deck. As you can see, it would take a very crowded deck full of big people to create a danger of an overload failure. A deck with more people on it than this would likely be difficult to achieve and resemble a Guinness Book of Records attempt more than a typical party.
The deck and balcony collapses that we hear about are almost always found to be the result of either improper construction or deterioration of the structure. We rely on inspections by trained local building inspectors and third party engineers to ensure balconies are built correctly, but they are not on site watching every fastener being installed and they do not inspect every nail. So sometimes small defects are missed, but potentially tragic issues rarely get by as these inspectors keep life safety as a paramount concern.