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Re: IRC Braced Panels

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Joe et al:
Here, in hurricane country of southern NJ, I also
never had a client or builder choose a full analysis 
and these are for homes facing the ocean with open
ceilings, huge windows, doors, etc.
Regarding liability, I have these clients sign a
release stating that they understand and accept the
problems with designing to the IRC prescriptive
method. I'm not sure that this will get me off the
hook if (when?) their insurance co doesn't pay for
damages caused by the next big storm, but its this or
no work.  

Irv 


--- Joseph  Grill <jrgrill(--nospam--at)cableone.net> wrote:

> Ted,
> 
> I'll disagree with you here.  From what I have seen
> the IRC is not fairly 
> restricted but extremely abused.  As in my last
> reply, I have seen way too 
> many homes being allowed to be built by the IRC that
> shouldn't even be 
> considered by the building officials.  There are no
> guidelines in the code 
> as to when the IRC can be used other than whether
> the structure is "unusual" 
> or not.  There is no definition of what is unusual. 
> Some have said that 
> there are definitions to that regard in the seismic
> section of the IBC, but 
> that is kind of like a definition twice removed. 
> Building officials won't 
> go to the IBC to the seismic sections to restrict a
> home that is built in 
> wind areas when the criteria in the IRC doesn't
> point them there.  What they 
> see is a simple sentence giving no guidelines for
> what is unusual and then 
> make a judgment from there.  Building officials in
> my area simply don't make 
> that judgment they just see that is a residence and
> say OK it can be built 
> by the IRC.  I have had architects, designers, and
> builders come to me with 
> 5000 sq. ft. plus homes with many offset dimensions
> in plan, many offsets in 
> roof diaphragm elevations throughout the structure,
> no load paths to walls, 
> etc, etc.  The building official might ask that one
> or two exterior walls be 
> checked as shear walls, and only then because they
> may not be the minimum 
> length per IRC.  When I have explained this problem
> to the potential client 
> I have NEVER had one ask for a full lateral
> analysis.  Why spend a couple 
> thousand when a couple hundred will get them their
> permit?
> 
> If the big wind or earthquake does come where then
> will the liability fall? 
> I can just hear it now "well gee, I had an engineer
> look at it, and his name 
> is "Brand X" engineering.  See here are his
> calculations."  And if we don't 
> do it, we engineers in Smallville don't pay our
> bills.
> 
> J. Grill
> 
> 
> ----- Original Message ----- 
> From: "Ted Ryan" <coffeemonkey100(--nospam--at)hotmail.com>
> To: <seaint(--nospam--at)seaint.org>
> Sent: Tuesday, January 11, 2005 10:07 PM
> Subject: Re: IRC Braced Panels
> 
> 
> > Again, missing the point.  Regardless of whether
> the IRC calc's out or 
> > not,
> > homes built in a manner consistent with the IRC
> generally perform well in
> > high seismic or wind events.  The IRC takes into
> account the redundancies
> > that we aren't able to in design.  The
> applicability of the IRC is fairly
> > restricted so that it isn't used in situations
> where an engineered design 
> > is
> > warranted.
> >
> > Ted Ryan
> >
> >
> > ----- Original Message ----- 
> > From: "Dennis S. Wish, PE"
> <dennis.wish(--nospam--at)verizon.net>
> > To: <seaint(--nospam--at)seaint.org>
> > Sent: Monday, January 10, 2005 5:51 PM
> > Subject: Re: IRC Braced Panels
> >
> >
> >> I think most of you know my strong views against
> the IRC (well the UBC
> >> Section 2320 for Prescriptive light framing) in
> high risk areas. This
> >> also includes areas open to high winds that might
> not be at risk from
> >> earthquake and wind.
> >>
> >> My first complaint is that the braced panel is
> not required to resist
> >> overturning by installation of holddowns. I've
> run an equivalent
> >> analysis on a small 40-foot wide home with a tile
> roof and with 4'x8'
> >> braced panels at 25-feet on center. The load to
> the panel was sufficient
> >> to cause an uplift on the wall regardless of the
> dead load from the clay
> >> tile roof. In most areas, clay tile is not an
> issue and asphalt shingle
> >> is more likely.
> >>
> >> The only reference I recall to resisting uplift
> is if you use an
> >> alternate braced panel 2'-8" wide up to 10'-0" in
> height in which case
> >> it is only required to resist a load of around
> 1800 pounds of uplift (or
> >> maybe it was 1500 pounds). The point is that it
> won't calc out.
> >>
> >> So what purpose does it serve to have an
> engineered code that
> >> consistently gets more aggressive in designing
> for better performance by
> >> using more plywood or proprietary shear walls and
> more hardware? Given
> >> the choice, a developer will go for the least
> cost and greatest profit.
> >>
> >> Here is another thing that drives me nuts. Every
> year I drive from
> >> California (Palm Springs area) to Chicago. I look
> at all the new
> >> developments in Arizona, New Mexico, Texas,
> Oklahoma, Missouri and
> >> finally Illinois. The one state that uses the
> least materials and is at
> >> the greatest risk is California. The majority of
> housing tracts that
> >> I've seen in Arizona and New Mexico will actually
> sheath the entire
> >> home. Yes, I believe they still cut back on some
> of the hardware that
> >> might help resist uplift, but they are not stingy
> on sheathing. Yet in
> >> California you will find tract developers cutting
> the amount of
> >> sheathing on prescriptively built homes (those
> smaller developers who
> >> are building around ten homes a year) to those
> large developers catering
> >> to the more affluent who still want to cut back
> on sheathing in order to
> >> maximize profits. They push their engineers
> (larger tracts are almost
> >> always engineered) to design with the least
> materials possible.
> >> In the heat of an argument with the construction
> manager for Sunrise
> >> Corporation, I was told simply that this is a
> free enterprise system and
> >> if his engineer can design it with the least
> materials to pass the
> >> permit stage he is free to maximize his profit
> margin for the company he
> >> works for.
> >> Yet none of this information is ever disclosed to
> the home buyer who has
> >> to pay the price of their deductible (if they
> have sufficient insurance)
> >> to cover their out-of-pocket costs.
> >>
> >> Look, we know it is not a life safety issue, but
> the housing industry
> >> can consider the financial impact poor
> performance will have on the
> >> homeowner, the insurance industry and the federal
> government in grants
> >> and low interest loans to help pay for the repair
> for qualified
> > homeowners.
> >>
> >> Is this really justification for a free
> enterprise system or for
> >> temporary housing before the cost of real estate
> rises to house the more
> >> affluent who will pay even a higher premium for a
> home built
> >> prescriptively to the Residential Codes.
> >>
> >> Doesn't make a lot of sense to me.
> >>
> >> Dennis S. Wish, PE
> >>
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=== message truncated ===



		
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