plywood shear wall using gage steel wall framing 2

[rlflower]

I am an engineer in Southern California looking for ICBO and LA City approval for a shear wall system consisting of plywood attached to steel studs with screws. I have a few projects ahead that will be ideal for such a seismic system, and I think it would be an improvement from the code approved nailed plywood shear panels to wood studs.

I know that there is Federal approval for just such a system, but it is only approved for seismic zones 1 and 2. My progects will be in seismic zone 4.

I am presently conversing with the manufacturer of Grabber screws to see if they have such an approval.

Simpson Strong-tie might also be interested; I am waiting to here from them. By the way, they just got LA City approval for various connectors for gage steel framing (RR25489).

 

[Taro]

Check UBC Section 2219.

 

[rlflower]

Thanks, but I find myself unfairly limited by the requirments of Section 2219. The gage metal allowed is limited to a gage that is thinner than what I would prefer to use. If I wish to use a thicker gage metal for my stud framing, where will I find approval??

 

[Taro]

The allowable shear values are based on empirical testing. Therefore, the stud thicknesses are limited to the thicknesses used in the tests. See

http://www.steelframingalliance.com/pubs/shear.pdf

for more information.

 

[mavmerl]

You may also want to look at

http://www.steelnetwork.com.

They have proprietary systems using cross bracing (somewhat like using a Simpson Strongwall). I don't know if they have ICBO approval on their products.

 

[rlflower]

Thank you, Taro.

 

SEE ER-5585 & NER-272, & OTHER MANUFACTURERS OD SCREWS, PNEUMATIC FESTENERS.

 

[rlflower]

A thank you to everyone who has responded to this thread. However, it appears that the City of Los Angeles is just not "up to speed" with regards to gage metal wall framing, let alone to use such a system as a shear wall panel. As it turns out, there are questions with regard to energy and fire requirements that make the use of gage metal framing cost prohibitive. It appears that the gage metal is much less resistant to fire than conventional wood stud framing.

As a result, we are forgoing the use of gage metal wall framing on our projects.

And so, my needs for this thread have been met. If anyone out there desires to continue this thread, feel free to do so.

 

[boo1]

Your statement:
"It appears that the gage metal is much less resistant to fire than conventional wood stud framing." Does not make since.

While heavy wooed beams would char and retain strength, any substatial fire would consume a 1 1/2 thick pine member in very short order.

 

[Mattman]

There is a product in California that I wish we had in Chicago: Sureboard, a 22 gauge steel sheet laminated to drywall. Better yet, it has been approved by ICBO and the City of Los Angeles for light gauge shear wall design. This may be your solution. Check out the approvals, tests, and design values at:

http://www.cemcosteel.com/evaluation_reports.asp

No, I am not affliated with Sureboard, nor have I used it, but it does look promising.

 

[jcox]

As far as the fire rateing is concerned it's not always the flame but the heat that affects the strength of the material. Wood can maintain it's strength longer at high heats for a period of time, light gage steel can quickly lose strength when the temperature is high enough.

 

[rlflower]

OK, I'm back. You have "tickled my ears" with promising news.

I have downloaded the ICBO Report and LA City Research Report for Sure-Board Series 200 Structural Panels. My Question is: How do I determine the fire rating of this panel, installed with gage metal wall stud framing? (I am not that familiar with the fire code, so bear with me). These reports say nothing about the fire rating.

 

[Mattman]

Sureboard is fabricated from 5/8" Type-X gypsum board and can be substituted for it in fire-rated assemblies.