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Re: Berkeley Balcony Collapse

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Removal of the existing lower balcony sounds fishy at a minimum and
criminal at a maximum. But I think most of us engineers involved in this
discussion know what happened at this point, and know how to prevent it.
Chuck's breakdown previously was great. I would add that maybe they need to
just do away with wood materials in exposed structures such as balconies
due to the critical nature of those parts of the structure, and the
catastrophic failures that can occur with no warning in the case of wood
decay. That is, elevated, cantilevered balconies without roofs. I am not
talking about exposed wood decks supported by posts.

Steel channels, form deck and concrete just are not that expensive, and if
it is in code then everyone is evenly competing (from a developer/business
interest viewpoint). Or require a roof with a minimum overhang to protect
the balconies if you want to use wood. Codes don't allow wood to support
masonry in general, right? Why exactly? Not for strength reasons, you can
design a wood beam to support the load of masonry. Is it because of fire?
Whatever the reason, it just feels right as a structural engineer doesn't
it, not supporting masonry with wood? Moisture in masonry could also affect
wood. Anyway, why not make special requirements for cantilevered balconies?

If the very basic purpose of building codes has always been to protect life
and provide safe structures, then this type of change would fit that ethos.
I don't think it is knee-jerk either, based on my experience and all those
who have shared on this subject, I am now surprised there are not more of
these types of failures. Perhaps there are but luckily with no loss of life
and perhaps the problems are caught before a failure.

I suppose at a bare minimum requiring a strip of ventilated soffit along
the wall-balcony junction would allow for easy inspection, allow for
ventilation, and allow water to drip down and possibly a problem to be
noticed. But depending on follow-up inspections and proper maintenance and
these types of things leaves to much in the hands of non-professionals that
have economic motivations.

I am already seeing that building science and weather proofing are emerging
as a specialty profession, and that is a good thing in my opinion. Firms
would specialize in these pieces/parts of the building design and
inspection, the way we have for concrete and steel inspections, and could
become part of the threshold/specialty inspection process. Owners will
complain about cost but repairs cost a LOT. And lives, well, they are
priceless....

Andrew Kester, PE
Florida

On Wed, Jun 24, 2015 at 7:35 PM, Abolhassan ASTANEH-ASL <
astaneh(--nospam--at)berkeley.edu> wrote:

> <http://cirrus.mail-list.com/seaint-seaosc/43155209.html>
> 
> --
> 
> Abolhassan ASTANEH-ASL, Ph.D., P.E., Professor
> 2013 Minner Faculty Fellow in Engineering Ethics and Social/Professional
> Responsibility and
> 2013-14 U.S. Fulbright Senior Research Scholar
> Department of Civil and Environmental Engineering
> 781 Davis Hall,  MC 1710
> University of California,
> Berkeley,  CA 94720-1710, USA
> Web: www.ce.berkeley.edu/~astaneh
> Web: www.astaneh.net
> Phone; (510) 642-4528

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