The summer holiday season is a time for celebration, but also a time of risk. Every year, large groups gather on outdoor decks, some of which have deteriorated over the years to the point where they can no longer carry the design loads. 2015 has proven to be no exception: disaster struck a July 4th family gathering at a beach house in Emerald Isle, North Carolina, sending more than two dozen people to area hospitals following a ten-foot plunge.
The collapse made national headlines: USA Today carried the Associated Press report (see: “14 hurt, 2 critically as deck collapses at N.C. beach house”). Police initially reported 14 casualties in the incident, but hospital sources told the AP that at least 20 people had been brought to emergency rooms.
The injured count kept rising: According to a final report from Emerald Isle town manager Frank Rush, 26 people were injured in the collapse at the vacation rental home at 4403 Ocean Drive. An investigative report by Carteret County, North Carolina, building official Chris Jones concluded that corroded fasteners were the weak link that brought an 8-foot by 10-foot section of deck crashing nine feet to the ground. Local station WNCT has that story (see: “Final NC deck collapse report: 26 hurt, corrosion to blame,” by Angela Green). The town of Emerald Isle posted the Carteret County report on the town website here, along with a description of the emergency response and a discussion of the town’s policy options for preventing future deck failures (see: “Deck Collapse Final Report”).
Photos attached to the Carteret County investigative report show joist ends with the embedded remains of several badly rusted nails, reduced to almost nothing by years of exposure to salt air and rain. No joist hangers are evident. The report describes the deck assembly as a girder system projecting from the house, with joists toenailed into the face of the girder. Says the report: “The floor system is constructed of 8-ft. 6-in. long wood 2x8 joist spaced 16 in. on center supported by a 2x2 wood ledger nailed to a double 2x10 wood girder spanning 10 ft. The wood girder is supported by two 6x6 wood post. The fastening system consists of nails and bolts. The joist appeared to be connected with 16d galvanized nails, the ledger appeared to be connected in the same manner, and the girder appears to be connected with galvanized ?-in. bolts. It appears from the evidence presented at the site the determination can be made that the collapse is a result of corroded fasteners.”
The thirty-year-old structure complied with applicable North Carolina building code at the time it was built, the county report noted. In a phone conversation with JLC, building official Jones said, “The assembly didn’t fail. It was the fasteners that failed.” Routine inspection, upkeep, and maintenance could have prevented the event, Jones said.
And Jones told JLC he sees no reason to think that the deck would not have supported this year’s Fourth of July gathering when it was new. “If you do the math, that number of people of average size would add up to about 4500 pounds,” he said — reasonably close to the code-specified 45 psf floor design load. But when the failure occurred, he said, the original fasteners were no longer competent. “There was really nothing holding those joists up but the five-quarter decking that lapped over the joists onto the girder,” he told JLC. “As soon as they put that weight on it, down it went.”
Carteret County is responsible for building permits and construction inspections in Emerald Isle, county Director of Planning and Development Eugene Foxworth told JLC. Residential decks, whether as part of a new house or as an addition to an existing house, require a permit application with plans, and new decks are inspected, he said. “But we don’t have authority to inspect an existing deck unless there’s a complaint of a building code violation,” he said.
In the final Emerald Isle town report, town manager Frank Rush wrote: “North Carolina General Statutes do not currently grant authority to NC cities and counties to conduct periodic building code or deck inspections of vacation rental units. Routine inspections of vacation rental units / existing homes are the responsibility of the property owner and / or property management company.”
With the latest serious failure incident fresh in their minds, Emerald Isle authorities are pondering their choices. Says the town report: “The Town will be soliciting input from various parties in the coming weeks, and will be discussing appropriate strategies to attempt to prevent such an incident in the future. Potential strategies to be discussed include enhanced public education efforts, pursuing potential changes to NC law, pursuing potential changes to the NC Building Code, strengthening the relationship with vacation rental agencies to promote deck safety, and/or other strategies.”