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[SEAOC] Metal Buildings

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My apologies to Metal Building Manufacturers, and the engineers who design
for them. I shouldn't have criticized them as I did in my reply to Valerie .
It's true what they say about the Internet, it's immediate, and it's
iretrievable!

Metal Building Manufacturers are solid and valuable members of the
construction industry, who generally provide good buildings to their
customers. Most of the suppliers to our market act quite professionally.

My motive in the reply was to encourage Valerie to stay with her high
checking standards.

My criticism resulted from experiences I've had with some suppliers, whose
shop drawings have shown structures which I've felt haven't come up to the
strength requirements of our National Building Code. After many
communications with the suppliers and their engineers, brace sizes have been
increased, beam sections and stability bracing has been beefed up, and the
designs have been accepted. I have been left with an impression that these
suppliers skinned the weight of their packages - cladding as well as frames
- to a bare minimum. Our better established suppliers don't seem to
interpret the Code as optimistically.

There were failures of some barrel vault style metal buildings in British
Columbia a few years ago, and our Professional Association has cautioned
members against automatic acceptance of metal building designs stamped by
temporary licensees. I haven't heard of complaints about the current group
of suppliers.

My theory to explain this is based on my observation that Metal Buildings
are often sold on price, in a highly competitive process. I can see that a
small weight and cost saving can make the difference getting a job. After
winning the job, the pressure to save weight continues if profit margins are
small. Saving 1/2 of 1% on the building might not mean much to an owner, but
it can mean a ten percent increase in profit, if profit is only 5%.

Design engineers working for these firms face the challenge of minimizing
material, while continuing to meet the Building Code. Earlier in my career I
tried to show my brilliance by reducing web member sizes in open web steel
joists, by using every analytical tool I could find to justify a high l/r
and save a small percent of the joist weight. Looking back, I wonder who I
benefitted by allowing a structural member which had little marginal
strength to deal with unexpected loadings.

Anyway, I still treat metal building shop drawings with extra care when they
come in, but I do respect the engineers and contractors in a very
competitive industry who generally provide a good product.

                                                                Jim Warne

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