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Re: Design for snow loads

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Daryl,
I can't agree completely. I know excellent engineers who work for excellent
manufacturers. I also know less-than-excellent engineers who work for
less-than-excellent consultants. Yes, all pre-eng buildings (metal or fabric
covered) should be checked out, just like a "conventional" building is
checked out - no more, no less.

Under-designed is a matter of opinion. Pre-eng manufacturers are not
consultants and should not attempt to determine the requirements of the
project - they are not insured to take that risk. They "size steel" and
detail assemblies. If they have delivered an "under-designed" product it is
usually a result of inappropriate specifications and insufficient monitoring
by the project consultant (or the result of NO consultant).

There are some bad apples giving the manufacturers a bad name: Brokers that
sell boiler-room style - "Oh? Did you want bolts with your building?";
Web-based resellers - "We happen to have spare inventory that we want to
clear this week ..."; Installers who throw the "sag rods" away because the
wall is up and the girts aren't sagging; Manufacturers who sell a wind-swept
roof-snow condition because nobody explicitly told them it shouldn't be and
the owner liked the price better. I've got a million of'em.

Just received a spec, today, for a Federal Gov't facility tender, issued by
a national consultant. I hope that the gov't isn't paying their fee because
my RFI is longer than the spec. The consultant does not appear to be taking
the role of building or structural consultant on the project and they are
relying on a broker-reseller (no engineers or architects) to define the
building requirements to the manufacturer. Since it is a Federal project,
the building department in the municipality will not even get a set of
drawings. One day, somebody will call this building "under-designed."

A roof failure blew across my desk, today (busy day). Manufacturer is
adamant that their design "met code" and they are not at fault. I suspect
that they are truthful in this response. I am trying to make the owner
understand that the performance definition in the spec may have allowed the
manufacturer to design to about 50% of the net uplift of the recent wind
event - but it met code. If they simply have the manufacturer replace the
roof, per spec and code, it will be gone again in another 5 years. It failed
prematurely but is this "under-designed" by the manufacturer or by the
specifying consultant?

Dissuade your customers and friends from dealing with the bottom-trawlers.
There IS a difference and you really do get what you pay for.

That was very long-winded of me. I must be feeling frustrated again.

Regards
Paul
-- 
Paul Ransom, P.Eng.
ph 905 639-9628
fax 905 639-3866
ad026(--nospam--at)hwcn.org


> From: "Daryl Richardson" <h.d.richardson(--nospam--at)shaw.ca>

> Paul,
> 
> I agree with your philosophy; but, in my experience, a large
> percentage of metal building manufacturers sell significantly under designed
> buildings.  My advice to anyone wanting to buy one is that they (the
> buildings, and I mean all of them) be regarded as suspect until someone
> knowledgeable checks them out.
> 
> Regards,
> 
> H. Daryl Richardson


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