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Re: Light ga. steel publ.

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I do specify the fasteners. Almost all of the residential I am doing is
residential for low income housing. For the most part, they are using
self-tapping sheet metal screws. For plywood shear walls, I specify the
Ply-metal drillers which have a metal wing on the end of the screw. This
widens the hole in the plywood and then shears off when penetrating metal
studs thicker than 18 gauge. The advantage is that the screw pulls the
plywood tight to the face of the studs. Without the Ply-Metal drillers, the
threads in the screw tend to tighten in the wood before the stud, leaving a
slight 'gap' between panel and stud. By enlargine the screw hole in the
plywood, the screw can rotate as it bites into the studs - thus pulling the
panel tight.
I have had contractors ask to use nails (like stud pins) but I follow the
guidelines of APA Report 154 for shear values on the panels. I don't
remember, but if allows pins (which I know it does) I let them use it.
However, our homes are being constructed in the field using sweat equity
from the future owner and free labor provided by Americorp Volunteers. They
are mostly women and non-professionals who are very limited as to the use of
power tools. Power driven pins are difficult for them to use and they find
it very easy to simply use screws.
Dennis

-----Original Message-----
From: Silva John (sj) <SILVA(--nospam--at)hilti.com>
To: 'seaoc(--nospam--at)seaoc.org' <seaoc(--nospam--at)seaoc.org>
Date: Thursday, January 15, 1998 12:46 AM
Subject: RE: Light ga. steel publ.


>Thanks for the clarification, Dennis.  Mind if I pick your brain a
>little more?  Are you designing a lot of residential steel, or is it
>mostly commercial?  Do you specify the fasteners?  Are contractors
>asking you to approve other fastening methods (clinching, nails, etc.)?
>
>J. Silva, SE
>
>> ----------
>> From: wish[SMTP:wish(--nospam--at)cwia.com]
>> Reply To: seaoc(--nospam--at)seaoc.org
>> Sent: Dienstag, 13. Januar 1998 20:13
>> To: seaoc(--nospam--at)seaoc.org
>> Subject: Re: Light ga. steel publ.
>>
>>
>> -----Original Message-----
>> From: Silva John (sj) <SILVA(--nospam--at)hilti.com>
>> To: 'seaoc(--nospam--at)seaoc.org' <seaoc(--nospam--at)seaoc.org>
>> Date: Monday, January 12, 1998 5:30 AM
>> Subject: RE: Light ga. steel publ.
>>
>>
>> >Dennis,  thanks for your response.  I've been following the
>> development
>> >of residential steel (as opposed to metal framing in general) from
>> the
>> >standpoint of whether this trend has got legs and why (I'm in R&D).
>> Any
>> >information from my colleagues regarding experiences with residential
>> >steel projects, pros and cons, outlook for the future, is welcome.
>> Same
>> >goes for feedback regarding fasteners.
>> >John Silva, SE
>>
>>
>> John,
>> The latest controversy has to do with the discrepency of the APA
>> report 154
>> which was date back around 1993 and the upcomming '97 UBC requirments
>> for
>> Steel Stud Shear walls. The APA report indicates the minumum stud
>> thickness
>> at 14-18 gauge for shearwalls with a failure mode in the studs rather
>> than
>> the plywood connection.
>> Professor Serette's work at Santa Clara University tested 20 gauge
>> studs for
>> shear walls. My understanding is that the tests were done at Simpson
>> Strong-tie on their shear rack. The 97 UBC recommends 20 gauge studs
>> for
>> shear walls.
>> I would be very cautious of using 20 gauge studs for shearwalls when
>> past
>> testing (non-cyclic) has proven that stud buckeling occurs at 16 or 18
>> gauge
>> studs before the panel connection. What is the basis for recommending
>> 20
>> gauge studs in the next code? Is the testing as reported by APA
>> wrong????
>> These questions need to be addressed. Until then, I'll stick with
>> specifying
>> 16 or 18 gauge studs in accordance with APA 154.
>> We have had some communication on the list regarding this subject, but
>> I
>> don't think it has been resolved since cyclic testing has not be
>> evaluated
>> (I believe it has finally been done) and published.
>>
>> Regards,
>> Dennis Wish PE
>>
>>
>>
>>
>>
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