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RE: "Blown Away"

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OPINION
 
I think the bottom line is public safety.


Sharon Robertson Bonds, PE
Salerno/Livingston Architects
363 Fifth Avenue, Third Floor
San Diego, California  92101
(619) 234-7471

	-----Original Message-----
	From:	Bill Polhemus [SMTP:bpolhem(--nospam--at)swbell.net]
	Sent:	Monday, March 05, 2001 7:07 AM
	To:	seaint(--nospam--at)seaint.org; aec-residential(--nospam--at)polhemus.cc
	Subject:	"Blown Away"

	Recently, an architect client of mine and I were discussing a
feature of a
	commercial building we were working on. He does lots of convenience
store/fast
	food combination facilities. One client has a "doghouse" at the
front entrance
	of the store, a "penthouse" type structure that allows a sign-logo
above the
	entrance that extends about eight feet or so above the parapet line.

	The doghouse itself is CFS supporting metal cladding, which sits on
the beams
	and joists of the main structure.

	The design drawings given me showed a CFS structure that was WAY
under-designed
	to resist code-specified wind forces, and I proceeded to design it
correctly,
	which made for a much "beefier" structure, particularly where the
roof members
	and overall connnections were concerned. When he saw this, he had a
negative
	reaction. "Too much", he said.

	I pointed out to him that we were building in an area where the
design wind
	speed is 120 mph (three-second gust). His response was "oh, that
doesn't matter,
	if they had a hurricane, the doghouse would just be blown off, and
they could
	build it back again".

	I had NEVER heard of this approach before! In essence, he's saying
"just design
	it to handle gravity loads and don't worry about wind, this is not
an occupied
	portion of the structure. If it gets scoured off, no big deal".

	Have any of you designed "components and cladding" type portions of
a structure
	under this approach? The architect insists it is perfectly valid:
"we do it all
	the time". Of course, this guy is the "Wal-Mart" of architects in
our market,
	and is used by developers here because he works cheaply, and doesn't
get in
	their way.

	I'm starting to rethink my relationship with him on this basis, but
I'd like to
	know if this is perhaps more commonplace than I realize, and if I'm
	"overreacting". I just can't imagine a building department anywhere
allowing a
	portion of a structure the possibility of being "blown away".

	Thanks.