Sheathing uplift rating? 1

[SteveFehr]

I have an uplift load of 125lbs per 16" stud transfered from the 2nd to 1st floor of a 2-story residence. If the sheathing plywood spans the floor and ties into the vertical studs above and below, would the sheathing alone (1/2" CDX ply w/ 6" nail spacing) suffice for uplift or are straps still required?

IRC 2003 is the cognizant building code here.

 

[UcfSE]

You would have to check the nail pattern, the edge distances and so on. You may also find an interaction between shear and uplift in the code. If you use plywood for uplift then you are taking away from the plywood's capacity for shear. All that has to be checked. Otherwise you can use straps or another hold-down system. Basically it comes down to not making assumptions or assuming load paths without checking them also, thoroughly.

 

[bjb]

Go to the APA website and download Technical Note E510: using wood structural panels for combined shear and uplift resistance.

 

[SteveFehr]

Thanks, that's exactly what I was looking for, they even have the calculations laid out for easy plug-and-play! Looks like I'll be fine, my uplift stresses are about an order of magnitude less than simple sheathing can handle in combined shear/uplift so I'm good to go. I'm going to strap the high shear areas flanking the garage regardless, though.

Here's the URL for APA's bulletins, if anyone else is interested:

http://www.apawood.org/level_c.cfm?content=pub_searchresults&pK=wind&pT=Yes&pD=Yes&pF=Yes