Need a book? Engineering books recommendations...

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

RE: l/600 or l/720 brick veneer light gage back-up

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Roger (and others),

What do you do when your wall heights exceed 10'? Not even No2 Doug Fir/2x6/16"o/c @ 70% of 90MPH wind loads will hold L/600 beyond this point.  This would occur in all gable ends with vaulted spaces, and walls in some of the higher end residences, and most light commercial buildings. And yes, we still build commercial with wood in my area. This is primarily due to the lack of metal stud contractors, and lack of experience of smaller generals in dealing with gauge metal work.

For openings, I'll end up spec'ing PSL king studs or TS shapes, and walls I end up either making the spacing closer or going to 2x8s (yeah, they all just love me for that).  This is one area where I get a lot of "where are the bodies" questions.  This is especially true as brick veneer homes have been around for so long, and most people never see a wall with cracks that are attributed to wind-induced lateral deflection.

At 07:47 AM 12/8/2004 -0600, you wrote:

Yes, I do.  The masonry people, both NCMA and BIA seem to come up with this recommendation about the time that steel stud back-up started to become more popular but I don t like steel stud back-up any more than they do.  Most people seem willing to accept l/600 for vertical deflection because of concern for masonry joints and the joints are even more vulnerable from lateral deflection; so why fight it.  The masonry associations have widely published their recommendations; it seems prudent to follow those recommendations in our lawsuit driven society.

 

Roger C. Davis

Architect

SDS Architects, Inc.

205 N. Dewey Street

Eau Claire, WI 54703

(715) 832-1605

 

-----Original Message-----
From: Ken Peoples [mailto:kspeoples(--nospam--at)lvta.net]
Sent: Wednesday, December 08, 2004 5:41 AM
To: seaint(--nospam--at)seaint.org
Subject: Re: l/600 or l/720 brick veneer light gage back-up

 

Thanks Brian,

 

Just curious, do you use the l/600 criteria?  Is anyone using this?

 

Best regards,
 

 

Ken

 

Kenneth S. Peoples, P. E.
LVTA
Lehigh Valley Technical Associates, Inc.
1584 Weaversville Road
Northampton, PA 18067

 

Phone: 610-262-6345
Fax:610-262-8188
Email: kpeoples(--nospam--at)lvta.net
----- Original Message -----
From: Brian K. Smith
To: seaint(--nospam--at)seaint.org
Sent: Tuesday, December 07, 2004 9:50 AM
Subject: RE: l/600 or l/720 brick veneer light gage back-up
 
Ken,
 
    I typically consider the "service" load to be the 10-year mean recurrence wind event.  This is typically considered 75% of the 50-year design wind.
 
 
bks
-----Original Message-----
From: Ken Peoples [mailto:kspeoples(--nospam--at)lvta.net]
Sent: Tuesday, December 07, 2004 7:26 AM
To: Seaint
Subject: l/600 or l/720 brick veneer light gage back-up
I know that BIA recommends l/600 to l/720 for a brick veneer back-up deflection limitation.  They say "for service loads".  What I am not sure about is what the design wind pressure for this condition should be.  Should this just be based on the same component and cladding design load used for the strength design of the studs or can it be a reduced wind load.  Table 1604.3 of IBC 2003 indicates that the deflection limit for exterior walls with brittle finishes should be l/240 and footnote f indicates that the load may be 0.7 times the design component and cladding loads.  This seems to be quite different form BIA's recommendation of l/600.  Perhaps a brick veneer is not considered a brittle finish?
 
Is the l/600 or l/720 specifically required somewhere else in the IBC?
 
Thanks for your help.
 
Best regards,
 
 
Ken
 
Kenneth S. Peoples, P. E.
LVTA
Lehigh Valley Technical Associates, Inc.
1584 Weaversville Road
Northampton, PA 18067
 
Phone: 610-262-6345
Fax:610-262-8188
Email: kpeoples(--nospam--at)lvta.net
******* ****** ******* ******** ******* ******* ******* *** * 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 ******* ****** ****** ****** ******* ****** ****** ********