Opening allowed in Segmented shear wall?

[GVCivilGuy]

For a standard segmented wood framed shearwall, is there a maximum opening size allowed prior to analyzing it as a shearwall designed for force transfer around openings. I have a 12" exhauset pipe from a propane fireplace exiting through my 4' shearwall. The building department is requiring a perforated shear wall calculation. This doesn't seem very practical.

 

[MiketheEngineer]

IBC/IRC2006 has some examples. Maybe that will help.

Good golly - these guys are getting more and more picky - but I send them Xmas cards every year because I get more business every year!!!!!

 

[GVCivilGuy]

I understand how to perform the analysis for perforated and how to transfer forces around and opening. My question is at what opeining size is this required? Or is in any opening?

 

[MiketheEngineer]

I don't know - but if the building official is asking for it - then it is too big...

They call the shots and the code says they can. Good luck.

 

[msquared48]

Effectively, the force per foot in your wall is increased locally by 33% locally at the opening. This is not small. I can see that some special reinforcing, increased nailing would be needed in the region. No additional holddowns though. A perforated analysis would be conservative here.

If the wall was 10 feet long, I would argue the point, but not at 4 feet.

Mike McCann
MMC Engineering

 

[GVCivilGuy]

Thank you all.

 

[dougantholz]

If you look at your Co factor (table 2305.3.7.2 in the 03 IBC) you can have a factor of 1.0. In other words openings that are small enough don't change the capacity of the wall. look at that and see if your "piers" still meet the code provisions. Sounds like a case of educating the code official to me.