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Re: ground snow v. roof snow - which is it?

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Scott,
The OBC Commission was set up for hearing appeals & so
is not such a bureaucratic nightmare. Of course they
can't change the codes, but often they are subject to
mis-interpretation.  I have had to appeal twice.
First, I designed an industrial plaza, with handi-capped
(oops p.c. term is barrier free) washrooms.  The code
had specified a min size but also offered alternative
lay-outs in supplementary guide, which I used.  The city
inspector came in during construction and said that to
comply we had to put the wash-basins outside the
washroom.  I appealed and the city wrote a letter
backing down before it went to the commission.
  The second case involved a big industrial building I
designed for a heavy machine shop.  Based on floor area,
the city wanted a gazillion parking spaces.  I pointed
out in appeal that the machines took up half the floor
space. It went to the commission and in one month ruled
against the city.  That's my experience for what it is
worth.
Gary


On 22 Sep 2005 at 9:54, Scott Maxwell wrote:

> Hey, you can appeal anything.  It just becomes a question of how much
> hassle and time you want to expend.
> 
> If you want an official interpretation of a provision in a material
> standard (i.e. ACI 318, NDS, AISC ASD or LRFD spec, MSJC/ACI 530, ASCE
> 7, etc), you will have to contact the committee that prepares them. 
> Each might handle such requests differently, but I believe that most
> handle them similarly.  I can only say how ACI handles such things. 
> If you want an official "code interpretation", then it must go through
> the full committee consensus process (i.e. someone on the committee
> proposes the draft interpretation, the committee debates it, it gets
> "word smithed" and tweaked/modified, and goes through the full
> consensus voting process just like a new provision).  This means that
> it can take at least 6 months or so (about the bare minimum) but
> likely longer.  And there is a fee to do it.
> 
> For model building codes, I believe that ICC has a process for
> requesting an official interpretation.  I don't really know what it
> is, but I would expect that there is a fee and it ain't likely to be
> quick.
> 
> And, of course, you can "fight it" (appeal or whatever you want to
> call it) within the local jurisdiction.  You can try to make your case
> to the code official that made the original interpretation and see if
> you can change their mind with a logical arguement.  If that does not
> work, you can try going to the "boss" (whether that is the head
> building official or trying to get "political" and convince some
> political stiff that the building official reports to).  Of course, if
> you go to extremes, you always run the risk of pissing someone off,
> who then may go out of their way to find legitimate ways to screw with
> you (kind of like not helping a contractor fix a mistake that they
> made...if they get pissed about that then the contractor may not help
> you with problems that you made or ramp up costs to the client in
> other areas.  Note that I am not say that this will happen, but that
> it could as there are people in every walk of life/profession that
> take the "get even" approach to life.
> 
> Scott
> Adrian, MI
> 
> 
> On Thu, 22 Sep 2005, Gary Hodgson & Associates wrote:
> 
> > Scott,
> > Do you not have a right to appeal?  In Ontario, if we
> > feel an official has erred, we can appeal to the Ont.
> > Building Code Commission for an interpretation or ruling.
> > Gary
> >
> >
> > On 21 Sep 2005 at 12:24, Scott Maxwell wrote:
> >
> > > I don't disagree with you, but you have to realize that not all
> > > states adopt the codes for required statewide use.  In some
> > > states, codes are adopted (and potentially modified/added to) by
> > > local jurisdictions (counties, cities, etc).  That _WAS_ the case
> > > in Michigan until recently. It was not until a handful of years
> > > ago that Michigan went to adopting a code (which they DO modify
> > > some), the IBC and IRC, for state wide use. It used to be that
> > > each local jurisdiction would adopt what they wanted. Lansing, MI
> > > had adopted a version of the UBC.  Most jurisdictions in the SE
> > > Michigan area adopted a version of the BOCA, but one city might
> > > use 1993 while another used 1996, etc.
> > >
> > > And the point is that the jurisdiction (state, city, county, etc)
> > > that legally adopts the codes can modify it as they see fit...and
> > > most do so.
> > >
> > > And beyond that, even in some states where there is a state-wide
> > > code adopted, it is a "minimum" code.  In otherwords, local
> > > jurisdictions (cities and/or counties) can still modify the state
> > > code _IF_ they make it more conservative (and requiring the use of
> > > full ground snow load rather than roof snow loads per ASCE 7 is
> > > more conservative).
> > >
> > > And like it or not, by and large the local code official is the
> > > "interpreter' of the code.  While it is certainly possible that
> > > they could interpret it wrong, it becomes a hassle (at minimum) to
> > > argue against such misinterpretations at times, to (at the
> > > extreme) bad thing for the well being of your project (the good
> > > old phrase of "I fought the law and the law won" comes to mind).
> > >
> > > Scott
> > > Adrian, MI
> > >
> > >
> > > On Wed, 21 Sep 2005, Jordan Truesdell, PE wrote:
> > >
> > > > I believe that the requirement to use ground snow would have to
> > > > be proposed and included in the legislation adopting the code,
> > > > or in subsequent published addenda.  Code officials, as far as I
> > > > know, do not have the right to change the building code, though
> > > > some feel that they do. That's the whole idea behind using model
> > > > codes. Otherwise, we're back to pre-national code times when
> > > > every jurisdiction makes it own rules. It may not be worth the
> > > > fight - its not our money we're spending by upsizing roof
> > > > structures - but the courts would likely side with the letter of
> > > > the law, and in this case the building code is extremely clear.
> > > > "Shall be determined in accordance with" doesn't leave much
> > > > wiggle room.
> > > >
> > > > Jordan
> > > >
> > > > Scott Maxwell wrote:
> > > >
> > > >  Jordan,
> > > >
> > > > Not so quick.
> > > >
> > > > You have a point, but then Jim does as well as local code
> > > > officials or states can "modify" the plain vanilla IBC (i.e.
> > > > adopt it with modifications/additions).  From my experience,
> > > > some local juridictions will require the use of the full ground
> > > > snow load as the roof snow load (i.e. no modifications to flat
> > > > roof snow load or sloped roof snow load). Now, it is my belief
> > > > that this is largely due to the IRC (which I believe REQUIRES
> > > > the use of ground snow load and does not PERMIT modifications
> > > > per ASCE 7) and local code officials not realizing that such it
> > > > not "required" if the design is an engineered design (i.e. IBC
> > > > is used rather than IRC).
> > > >
> > > > Scott
> > > > Adrian, MI
> > > >
> > > >
> > > > On Wed, 21 Sep 2005, Jordan Truesdell, PE wrote:
> > > >
> > > >
> > > >
> > > >  Jim, I think you've got is bass ackwards ;-)
> > > >
> > > > I quote, "Design snow loads shall be determined in accordance
> > > > with Section 7 of ASCE 7..." This is the first sentence of
> > > > section 1608 of the 2000 IBC (Snow Loads).  The ellipses referes
> > > > to the requirement that the roof load must not be less than the
> > > > roof live loads specified in the Live Load section, 1607.
> > > >
> > > > That's pretty cut and dried - engineers (actually, anybody) are
> > > > specifically allowed by the code to use any and all reduction
> > > > (or amplification factors) they deem appropriate, as listed in
> > > > ASCE 7. The code writers appear to have specifically allowed the
> > > > reduction of loads where allowed by the ASCE.
> > > >
> > > > As has been mentioned, the span tables are probably based on
> > > > ground snow loads, and should not be altered without analysis by
> > > > a registered engineer.  Ground loads are convenient, because
> > > > that's what's in the table.  I would suspect that the tables
> > > > also assume partial exposure, ventilated roof over thermally
> > > > isolated living area, Terrain Categories A, B or C, an
> > > > importance factor of 1.0, and no drifting conditions or sliding
> > > > surcharges, and - of course - no unbalanced loads.  Prescriptive
> > > > design has its place, but can always be overridden by proper
> > > > analytical techniques. (That doesn't always mean reduced loads,
> > > > btw)
> > > >
> > > > Jordan
> > > >
> > > > Jim Wilson wrote:
> > > >
> > > >
> > > >
> > > >  It seems as if the code writers have eliminated the
> > > > option of reducing snow load when using prescriptive
> > > > design.  Subsequently, it is up to the local enforcers
> > > > to decide if an engineered design is permitted to
> > > > include the reduction factors.  Does that sound
> > > > correct?
> > > >
> > > > Jim
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
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