Return to index: [Subject] [Thread] [Date] [Author]

Re: wood frame bldg deformation and windows

[Subject Prev][Subject Next][Thread Prev][Thread Next]
This is not entirely correct.  If you design a structure that is so loose
that it requires a caulk joint between a wall and window system that exceeds
(min. and max.) what the caulking manufacturer can warranty, you have a huge
problem on your hands.  Your drift has to be within the serviceable limits
of the curtain wall system being used.  You obviously must know what the
curtain wall system is since you had to account for it in the seismic
weight.

As part of the design team, it is our responsibility to explain to the
Architect/Owner the trade off between reduced steel tonnage (as say in a
steel frame situation) and taking the drift to the absolute limit and
potential effects on the curtain wall system and their bids.  I have been on
both sides.  On the one hand, you may sell your engineering prowess by being
able to produce a structure that yields less tonnage than your competitor,
but have to go back and stiffen your design because the precast/curtain
wall/glazing and caulking systems have tolerances that cannot accommodate
your design.  Or, there bids come in much higher than budgeted and everyone
is pointing the proverbial finger at the engineer.

But on a wood shear wall system!  Come on!

Keith De Lapp, P.E.
KDL Engineering


----- Original Message -----
From: Gerard Madden <
gmadden(--nospam--at)duquette-eng.com>
To: <
seaint(--nospam--at)seaint.org>
Sent: Tuesday, January 08, 2002 5:16 PM
Subject: RE: wood frame bldg deformation and windows


> Regis,
>
> I think what Conrad is saying that it is our responsibility as engineers
to
> comply with the drift provisions of the code - this is also true for the
> window contractor. It is not our responsibility to figure this out for
them
> (unless specifically retained to do so) and the architect should be
spec.'n
> a system or window frame design that can allow movement - in plane and out
> of plane if they want to avoid non-life safety damage.
>
> -gerard
> SF, CA
>