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RE: PEMB document/review

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> From: MSSROLLO(--nospam--at)aol.com
> The document for the PEMB discussion was put on the SEAINT website.
> The following address was sent to me for the locations.
> 
> http://www.seaint.org/listfiles/

A very impressive document. As noted, it is slanted toward PEMBs from a
Butler perspsective and there are other manufacturers with completely
different approaches to many of the items that you described.

I think that it should be pointed out that, for the purposes of
contracts and project specifications, there is a MAJOR difference
between a SUPPLIER and a MANUFACTURER (although, occasionally, the
supplier IS the manufacturer). The terminology is critical. This
complicates many of the coordination issues with the SUPPLIER and is
usually the source of most confusion in projects where a PEMB is
provided. The buyer should qualify the SUPPLIER and the MANUFACTURER
independently and in their ability to work together. This may affect the
number of extra items that are billed during the project.

The SUPPLIER is generally (not always) a "dealer" for a specific
MANUFACTURER. The SUPPLIER may be a steel erector, general contractor or
even a broker/project manager. The SUPPLIER may not have the first clue
about something as simple as appropriate environmental loads, design
codes, additional dead or collateral loads and how to assess them. These
are the people preparing the details for the manufacturer's quote and
supply. In some cases, the eng/arch project specifications may not be
presented to the manufacturer (this is not always bad).

The MANUFACTURER is typically a sub-contractor to the dealer and it adds
another level of contract (legal) separation between the
owner/EOR/architect and the MANUFACTURER. This complicates
communication/coordination with the MANUFACTURER as well as what the
MANUFACTURER will be willing to perform. Generally, dealers for the
larger manufacturers work hand-in-glove with the manufacturer and this
separation becomes almost invisible in practice. This is not true with
many others - usually, the smaller manufacturers.

I disagree with the definition of pre-engineered. All buildings are
ENGINEERED but a PRE-ENGINEERED product is one that has been designed
without a specific installation application and may be qualified for
many possible conditions. For many manufacturers, only the smaller
components and assemblies could now be considered truly pre-engineered.
The manufacturers would like to reduce the commonly used term to MB
instead of PEMB (e.g. the AISC certification is MB), mostly because of
the many obsolete, inaccurate, prejudicial, generalizations adhering to
the term pre-engineered.

Despite the fact that most primary framing is custom designed, some
legacy portions of the pre-engineered systems still exist. For Butler,
this is primarily their pre-punched secondary members which makes the 3"
module an imperative for efficiency. As noted, this requires that all
dimensions (frame/bay spacing, building width, etc.) should be on module
in order to make use of many of their standard assembly details. Other
manufacturers do not pre-punch but supply self-drilling fasteners. There
are cost implications for each approach.

In the same direction, the term RE-USED could be reserved for the case
of a truly RE-USED building where the building has been dis-assembled
and sold to be re-assembled at a different site.

As with any issue, if in doubt, consult a qualified professional before
you write the spec, validate a bid or accept EOR status involving
engineered structural products. The more complex the project, the more
important this becomes to successful completion and your professional
credibility.

-- 
Paul Ransom, P. Eng.
Civil/Structural/Project/International
Burlington, Ontario, Canada
<mailto:ad026(--nospam--at)hwcn.org> <http://www.hwcn.org/~ad026/civil.html>

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