City of Berkeley officials on Thursday released the architectural and structural renderings used to construct Library Gardens at 2020 Kittredge St., and there was no “smoking gun” that revealed a design flaw that might have led to Tuesday’s balcony collapse that killed six people and injured seven others.
The design for the balconies and their connection to the building appear to have been done correctly, according to Gene St. Onge, a civil and structural engineer in Oakland who reviewed the drawings.
“There is no question in my mind it was designed properly,” said St. Onge.
Read complete balcony collapse coverage on Berkeleyside.
The expert hired by the San Francisco Chronicle to review the documents said the balcony that collapsed was designed to hold near two tons – much more than the weight of the 13 people who crowded on it before its collapse.
Most experts who have examined photos of the balcony believe dry rot, a fungus that feeds on water, caused the wood beams to decay and weaken. How water got into the beams supporting the balcony is an unanswered question — and one that will be critical in determining who is at fault.
A photo of the balcony that fell and the one below it shows a huge difference in the quality of the wood structural beams. The wood on the failed balcony appears rotted and dotted with white mold; the one below does not.
“There wasn’t a structural failure per se,” said St. Onge. “It wasn’t because it was overloaded by 13 people. We’ve all acknowledged that it was a dry rot condition. It was severely compromised. It turned to dust in some cases. All you needed to do was have any kind of load on top. Maybe two or three people could have failed it. It (the balcony) was ready to go.”
The construction drawings called for two different types of waterproof membrane – Grace Co.’s “Ice and Water,” its top of the line water proofing, and Grace Bituthene 3000. The former was used.
For a long time the manufacturer said its Bituthene products were self-sealing, said Lloyd Dinkelspiel, a former building inspector for the city of Brentwood who also worked for a construction defect company. [Dinkelspiel is the brother of Berkeleyside Executive Editor Frances Dinkelspiel] A carpenter supposedly could nail the membrane in place and the product would close around it.
Grace later stopped recommending this, said Dinkelspiel. .
Library Gardens was constructed from 2005 to 2007.
The design drawings appear to have called for proper waterproofing, said Dinkelspiel.
“This is the crux of the matter – the waterproofing,” said St. Onge. “I would say it’s the most complicated aspect of the whole thing. It needs a serious study before we draw any conclusions. Whether the detailing was incomplete, or the implementation was not done right, or whether there was a product defect,” is the question.
While Berkeley planning officials oversaw the construction of 2020 Kittredge St., an outside firm, Linhart Peterson Powers Associates of Citrus Heights, California, also reviewed them. It is common for cities to outsource building reviews, said Dinkelspiel. The developer, John LeClercq and Transaction Companies, probably would have paid for the outside review.
When the plan for Library Gardens was first presented in 2001, the two balconies facing Kittredge were not part of the design. The architect changed the design in response to a critique by the Design Review Committee. The city board was concerned that the building – the largest apartment complex ever built downtown at the time – would overwhelm the street. The DRC suggested that the architect add the balconies to break up the façade.
Regardless, the balconies were built to code, according to the documents released Thursday.
The city of Berkeley is still investigating the cause of the collapse and will look at everything, from the design to the construction to maintenance after the building opened, said Matthai Chakko, a city spokesman.
Attention will definitely be paid to the contractor, Segue Construction, Inc. Pleasanton, which has been sued previously for water intrusion in the some of its projects. Segue reportedly settled one case regarding an apartment complex in San Jose for $3 million and was involved in another $3.5 million settlement in 2013 in Millbrae related to waterproofing and wood rot. And, that same year, Trestle Glen Associates, in Colma, filed a breach of contract lawsuit, still underway, against Segue related to “water intrusion causing tangible property damage.”
Sam Singer, a PR specialist hired by Segue, said that the company has a long track record of safety and quality, and that lawsuits are “commonplace” in the construction industry.
A photo from the San Jose apartment complex, The Pines, involved in one of the lawsuits against Segue, shows how water intrusion rotted out the beams in an elevated balcony. (It is a different design than the cantilevered balcony that collapsed at Library Gardens.)
The Library Gardens complex is made up of two buildings of 160 one- and two-bedrooom units. One building faces Kittredge Street and one faces Milvia. BlackRock, a huge investment management firm with more than four trillion dollars in assets, acquired the building for around $65 million in 2007. It hired Greystar, a Houston-based real-estate company, to manage the property.
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