Toenailing for shear transfer 1

[rbach]

Under the UBC in seismic zones 3 and 4 per 2318.3.1 (1997 UBC)toenails are not allowed to transfer lateral forces in access of 150 plf from diaphragms to shear walls, etc.. In some (very rare) of the designs I've seen toenails are used in combination with Simpson A35's (or other metal connectors). Is this an acceptable design? I see this as analogous to rigidity analysis where the stiff element,the A35 connector,will take the load and the flexible element, the toenail, will not see the load until the stiff element fails/deflects. Your thoughts please.

 

[SperlingPE]

If toe nails are not allowed I would design the connectors to take the entire load. The toe nails are there for alignment during construction and would not factor into my calculations for capacity.

 

[cap4000]

Check the NDS 8.8.5.6 & NDS 8.8.7.1 Specs. I have a 1990
publication that gives the "lateral capacity" of toe nailing as 5/6ths and the "withdrawl capacity" as 2/3rds the straight full penetration values. Also it mentions,if you use metal side plates and rigiditly nail the connection, you can increase it by 25%.Having said this,I would use the UBC as the governing Code,and consider the toe nails as only your connection insurance. Good Luck.

 

[baritone6foot4]

I rarely see a correctly installed toe nail. I wouldn't include them in my calculation.

Brian K. Willis, PE

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