Need a book? Engineering books recommendations...

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

Re: Styrofoam seal at plywood shear wall sill plate & bad EN

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Exactly the point Sasha. Funny, because it's true, Sad because it's true.

All these mathematical gymnastics required when performance of a wood building boils down to a few main things: Load path and quality of construction.

Drift checks for shearwalls that have shiners, no mandatory inspection to assure the framers are even close, over nailing, wrong sheathing, sheathing left bare to get rained on over and over? What's the point in this precision in calculation when the construction is anything but precise?

Even DSA has realized this. They have an IR for wind loads out now that basically reverts back to 97UBC methodology. I plan to use it.

-gm

On Jan 23, 2008 6:42 PM, Alexander (Sasha) Itsekson < sasha(--nospam--at)enginious-structures.com> wrote:
Gerard, I think it is very funny but is also so SAD!!!  How did we end up with this new code?  Why aren't there exceptions for simple small light frame buildings?  I can't remember the name of a very wise engineer who kept asking this list years ago " Where are the bodies?"  I don't think that by making our work ever so complex using ever so "scientific" methods (redundancy anyone?) makes our buildings any better or their behavior more predictable.

Chuck and others: Thanks for your input.  That makes a lot of sense and is exactly what I am going to direct him to do - remove the plastic and replace with drypack or similar.

Best,


Alexander (Sasha) Itsekson, SE
Enginious Structures, Inc.
Oakland, CA
510.272.9999
www.Enginious-Structures.com







-----Original Message-----
From: Chuck Utzman [mailto:chuckuc(--nospam--at)pacbell.net]
Sent: Wednesday, January 23, 2008 1:19 PM
To: seaint(--nospam--at)seaint.org
Subject: Re: Styrofoam seal at plywood shear wall sill plate & bad EN

Bill Allen wrote:
>
> ROFLMAO!
>
> T. William (Bill) Allen, S.E.
>
> ALLEN DESIGNS <http://www.AllenDesigns.com>
>
> Consulting Structural Engineers
> V (949) 248-8588 * F(949) 209-2509
>
> -----Original Message-----
> *From:* Gerard Madden, SE [mailto:gmse4603(--nospam--at)gmail.com]
> *Sent:* Wednesday, January 23, 2008 11:55 AM
> *To:* seaint(--nospam--at)seaint.org
> *Subject:* Re: Styrofoam seal at plywood shear wall sill plate
>
> There goes that whole rigid diaphragm of wood walls idea....add a new
> factor in the in-plan ewall deflection calc for rigidity...crushing of
> the styrofoam
>
> Delta_sty = e^log23 * (coeff. per ASCE 7 section 128.1.5.a exception
> #3 ) x E of styrofoam x Phi
>
> -gm
>
It isn't funny. Shear won't be a problem but if you put this stuff under
a shearwall post it will crush under cycled loading. Premature failure
of the nails at the bottom corner of the shearwall & excess deflection
are almost certain. Make them remove it at the SW corners & & slide in a
non-compressible shim.
Chuck Utzman, P.E.
p.s. On a somewhat related note--how do you guys deal with SW edge
nailing over 350 plf when they fail to stagger the nails? I've been
treating it like over-driven (add one for every two bad ones).








c







******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
*
*   This email was sent to you via Structural Engineers
*   Association of Southern California (SEAOSC) server. To
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you
*   send to the list is public domain and may be re-posted
*   without your permission. Make sure you visit our web
*   site at: http://www.seaint.org
******* ****** ****** ****** ******* ****** ****** ********

******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
*
*   This email was sent to you via Structural Engineers
*   Association of Southern California (SEAOSC) server. To
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you
*   send to the list is public domain and may be re-posted
*   without your permission. Make sure you visit our web
*   site at: http://www.seaint.org
******* ****** ****** ****** ******* ****** ****** ********



--
-gm