Andy,
My response to your last point
- 10’-0” high 2x4’s… exactly why I initially called for 2x6 stud walls, but the GC is flipping out about it… I get the old, “I’ve been doing this for 30 years, and never had to do this before”…
I typically will the contractor that the codes has changed a lot in the past 30 years. Grading of wood stresses has also changed in the past 30 years.
Marlou Rodriguez, S.E.
MBRodriguez Engineering Inc.
Tel: (408) 432-4866
Cel: (408) 761-5013
From: Andy Heigley [mailto:aheigley@jgaeng.com]
Sent: Friday, July 13, 2007 12:39 PM
To: seaint@seaint.org
Subject: RE: Wood interior wall studs
Everyone:
Thanks for your responses…
Here are my responses to some of your questions back:
- I would design for LL and LLr if the wall were supporting both the floor and roof loads.
- I am designing to ASD.
- I guess I’m a little leary of using the Cd of 1.6 for this reason. The duration factor is applied to both bending and axial capacities. Applying 60% more to the allowable axial stress makes a huge difference. And if you have a 4 story building, for example, you are going to be approaching the capacity of the stud just due to DL and LL… you then add a “little bit” of short term horizontal loading to the stud and increase the capacities by 60% seems non-conservative.
- Scott: I haven’t found the rated wall design reduction factors you’ve mentioned. Can you tell me the code section that is in?
- 10’-0” high 2x4’s… exactly why I initially called for 2x6 stud walls, but the GC is flipping out about it… I get the old, “I’ve been doing this for 30 years, and never had to do this before”…
Andrew Heigley, PE