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Re: CFS gage on drawings

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Brad,

I have worked a few years for a LG contractor and
still provide calcs for some local contractors from
time to time.  IMO, engineers who don't do their due
diligence in providing necessary stud sizes are doing
so to save themselves time and money and in the end
probably doing an injustice to the owner.

Sure there a lot of different cases, but quite often
the calcs come back from submittal marked "reviewed
for loads imposed on structure."  Not only did the SER
not want to bother doing the design up front, they
didn't want to review it on the tail end because it
already has someone else's stamp on it.  I have hired
these outside engineers before, and they are likely do
do a very quick and dirty job (myself excluded of
course).  Some are working from their dining room
table, much as I am right now, working on a very tight
contractor's budget.

And any contractor's designer is likely to miss the
SER's intent in one way or another.  I run into that
quite often trying to understand the S-drawings and
the A-drawings and guessing at the details.  I try to
flag it in my calcs, but that sometimes goes nowhere. 
There is no time for RFI's when the contractor is
hanging studs tomorrow.

Furthermore, if the SER provided a complete design of
the LG system, they would realize more of the holes in
their own designs.  Architects tend to show studs in
places where they are supporting windows and connected
back to air.  I've seen a lot of major design issues
that had no excuse for being approved in the first
place.  Fortunately for many engineers, our company
was too stupid to claim extra work and they signed
contracts for design drawings as is.

Now, putting on my SER hat, perhaps my opinion is
biased, but I still believe that it is the SER's
obligation to provide a complete biddable set of
drawings and specs.  The only thing that should be
left to the contractor is manufacturer and connection
type.  I wouldn't bother spacing items like PAF's
unless I was feeling particularly gratuitous.

Stud joints should also be shown.  I've seen
horizontal slip joints midway between floors with
finished drywall covering them.  How bad is that!  But
the design drawings left absolutely no choice and they
engineer and architect accepted it.  Had it been
considered properly in the first place, that problem
wouldn't have occurred.  I pity the building owner who
gets complaints from residents because their walls are
cracking.  That will be a fun fight I won't be a part
of.

And in the end, isn't the final design going to fall
back on the SER anyway?  I wouldn't want to be the one
that blindly accepted a contractor's calc, nor would I
want to be the one to pay for the change order because
it wasn't designed completely or properly.

Sorry for the long response, I am procrastinating from
my light gage framing side job and you struck a sore
subject.

Regards,
Jim Wilson, PE
Stroudsburg, PA


--- bbyrom(--nospam--at)vollmer.com wrote:

> I'm am trying to get an idea of what others are
> doing in practice.  I have
> completed a couple of jobs where I showed the size
> and gage of exterior
> non-loadbearing CFS wall studs in section (or gave
> the architect a gage for
> his sections).  The contractor bids on the job using
> that gage, the CFS
> manufacturer completes the design which changes some
> of these sizes, and the
> contractor submits a change order for the
> difference.  Since I am ultimately
> not responsible for the final design of these
> elements, I am leaning towards
> not giving a gage on drawings in the future.  I
> assume that this would
> require a bidding contractor to have the CFS sub do
> a preliminary design for
> pricing, but it would relieve me from the
> responsibility.  Is this standard
> practice?  What if the architect insists on showing
> the gage?
> 
> The reason that I ask is that I keep getting burned.
>  For example, I told an
> architect that 20 gage 6" studs were adequate behind
> a brick veneer with 10'
> flr to flr.  I checked the studs for L/600
> deflection and bending, and they
> were fine, but it turns out that there is a
> requirement in the masonry code
> for 18 gage min.  Over a large project, the
> increased cost becomes rather
> significant.
> 
> Any thoughts are greatly appreciated.
> Brad Byrom
> 
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