Wood - Segmented Shear Wall - Double Sheathing

[bookowski]

Per IBC the shear value using the perforate wall design method may not exceed 490plf, or for wind 1.4 x 490 = 686plf. If I have double sheathing can I double that value?

 

[woodman88]

I never checked if the 2003 IBC allows the increasing of the 490plf for double sided.

But from what I see in the AF&PA SDPWS-2005 (referenced in the IBC 2006?) and the AF&PA SDPWS-2008 (referenced in the IBC 2009 & 2012) I would say no.

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

 

[bookowski]

Thanks - Does it explicitly state that you can not increase for double sided or is that your interpretation? I couldn't find anything either way.

 

[jdgengineer]

I agree with woodman, I don't believe the code allows you to double it. Although, personally I typically never use perforated walls. If I'm going to put an opening in a wall I'll just use the Force Transfer Around Openings Method. Once you have a spreadsheet developed it takes only about a minute or two to do the analysis, and I believe it is much more rational. I suppose, the only time I would be tempted to use a perforated wall would be if the opening was a door, as it is my understanding that the Force Transfer Method may not apply in those situations (although some engineers try and use the rim board below). The times I have run across this have been few and far between and its just easier to add the extra holdowns you would have based on the segmental approach.

 

[woodman88]

Well you can do a double sided shearwall (Say you use a 290 plf nailing/sheathing on both sides) and increase the shearwall up to the 490 plf maximum. But going over the 490 plf is not allowed, as I see it. But again, I have never look into going above the 490 plf for this condition.

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

 

[bookowski]

Got it, thanks.

I'm rebuilding a wall to match an original condition and finding that it doesn't come close to working. Makes sense to me but the architect doesn't understand that 'it doesn't work' when it was standing just fine for 100 years. I'm trying to squeeze every ounce out of it to get it to work.