Wood shear walls using metal strapping 1

[tmills]

Do any of you have any details or experience with using galv. metal straps for X bracing in wood stud shear walls. This would be for internal shear walls on multi-story wood framed buildings. I have seen them used on other projects by other firms but we can't get comfortable with the numbers using nailed strapping. Are there products out there designed for this application? We usually will default to a plywood shear panel with Simpson floor to floor ties.

Are there any good references on this subject?

 

[DaveAtkins]

If you are talking about "let-in" bracing (the tee shaped sheet metal stuff), then its capacity is about zero, as far as I know.

You are correct--the problem with diagonal straps is that you can't get enough nails or screws into the stud at the strap location.

Perhaps you could use steel studs at the locations where you need shear walls. Straps work well with steel studs.

DaveAtkins

 

[tmills]

Thanks Dave; but no. I'm refering to 2" flat straps that are nailed in an X brace arrangement from top plate to bottom plate. What I have seen is the use of a double studs at each end of the brace and nails tieing the straps to each stud. I odn't see how you get much from this.

 

[MiketheEngineer]

You don't and you are right...

APA rated OSB seems the best way

 

[csd72]

tmills,

This is standard practice in Australia, but as stated before the capacity is limited by the nails.

This is prydas Australian design guide on this, you may want to see if they produce something similar for the US.

http://www.pryda.com.au/uploads/Product Guides/Bracing.pdf

csd

 

[msquared48]

Unless it is a tested system, i.e., ICBO rated, I would stick to the IBC values. The critical, limiting connections would be to the top and bottom plates. This would also fall into the "tension only" realm of lateral bracing. If you need higher shear wall values than listed in the IBC, look tho the Simpson catalog - these systems are ICBO tested and rated.

Mike McCann
McCann Engineering

 

[structuralaggie]

The Simpson Strong-Wall Shearwall is the only one I know of that makes use of straps, although I don't think they are diagonal. I wouldn't try to site build one of these, though. Quality control would be tough.

 

[msquared48]

No, they are not diagonal. I don't know of one that is...yet.

Mike McCann
McCann Engineering