A city analysis of the balcony that collapsed last week, killing six and injuring seven, revealed that the balcony was severely dry rotted at its breaking points.
Based on the analysis announced Tuesday, city staff recommend that Berkeley adopt new and modified regulations, including stricter requirements for waterproofing, inspection and ventilation on new balconies and other areas exposed to weather.
The regulations would also require regular maintenance inspections of both existing and new balconies, according to city spokesperson Matthai Chakko. These inspections would occur about every five years on all new and existing multifamily buildings and would begin within six months of adopting the new code.
The balcony below the one that collapsed was similarly dry rotted, although the city determined other balconies at the site, connected to Units 204 and 244, to be structurally sound.
The city’s Building and Safety Division staff also confirmed that the plans for the balcony complied with all the applicable California building code requirements in effect at the time and that all state-mandated inspections were conducted.
At a press conference held Tuesday afternoon, city planning and development director Eric Angstadt said the proposal to City Council “will address the many different ways moisture could get into wood” because the city’s analysis did not conclude a formal cause of moisture infiltration into the balcony’s structure.
Specifically, changes in regulations would require ventilation of each separate space within the structure of balconies and other building elements exposed to weather and would require that these structures be built with naturally durable wood or similar approved materials. The city’s recommendations also strike out an exception to using naturally durable wood when that wood is covered by an “impervious moisture barrier.”
At the press conference, Angstadt said it is not surprising for a building less than a decade old to experience the levels of dry rot found on the balcony, given how quickly the fungus can advance. He added that the building’s design should have been able to support 13 people, agreeing with the analysis of structural engineer Gene St. Onge in his independent investigation.
The city is not pursuing any further investigation or materials analysis, Angstadt said. Berkeley authorities, however, have joined a criminal investigation led by the Alameda County District Attorney’s Office, according to an SFGate report.
San Francisco trial attorney David Anderson, who attended the conference, said the most important next step is to enforce the potential new regulations.
“Property owners can comply with building codes, but those are just minimum standards,” he said. “If the city doesn’t take a step forward … beyond state law, these new regulations might as well not be there.”
On June 16, after the collapse of Unit 405’s balcony — which was located on the fifth floor of 2020 Kittredge St. — building inspectors visually examined the exterior of the building, noting that the wooden supports for the balcony sheared off about 16 to 20 inches from the exterior building face and that the broken ends suffered severe dry rot, according to a memorandum from the city’s Building and Safety Division. The balcony hinged downward to rest against the building’s wall and was supported by the balcony guardrail of the Unit 305 deck below.
At the end of the same day, the collapsed deck was removed, and debris was cleared away. After exploratory openings were drilled into the bottom of the Unit 305 balcony, the balcony was deemed unsafe because of dry rot.
In subsequent days, Unit 305’s deck was removed, and dry rot on the deck joist ends was confirmed. Analysis of the two other decks in the building indicated that they did not have the same structural support system and showed no signs of distress or water damage
City staff are prepared to present their proposal to City Council at its July 14 meeting. If all the recommendations are passed, they will be sent to the state for ultimate approval.
Check back for updates.