Bracing to resist lateral loads due to wind and earthquake (Canada code question)

[CANeng11]

I am looking for clarification on section 9.23.13.1(2) of the National Building Code of Canada.

2) Bracing to resist lateral loads shall be designed and constructed as follows:
a) exterior walls shall be
i) clad with panel-type cladding in accordance with Section 9.27.,
ii) sheathed with plywood, OSB, waferboard, fibreboard, gypsum board or diagonal lumber sheathing complying with Subsection 9.23.17. and fastened in accordance with
Table 9.23.3.5.-A, or
iii) finished on the interior with a panel-type material in accordance with the requirements of Section 9.29., or

So part a)i) states it must be clad with panel-type cladding. What exactly is "panel type" cladding from part 9.27? Would that be only plywood, Hardboard, or OSB and Waferboard cladding in addition to the plywood sheathing? So if it isn't one of these three types of cladding(say it is stucco) then you have to jump to part 2b for design and part 2a isn't applicable?

 

[jayrod12]

You have a situation where you have stucco but no sheathing? Seems odd.

Edit: thinking about it further, I think you're asking if the actual cladding changes which method to use. I don't have my code handy at the moment, but I can't see that. Can you post what part b says?

 

[CANeng11]

Ya that's exactly it, I wondering if the type of cladding changes the method I have to use because it says clad with a panel type cladding. Part B is

b) in accordance with
i) Articles 9.23.13.4. to 9.23.13.7.,
ii) Part 4, or
iii) good engineering practice such as that provided in CWC
2014, “Engineering Guide for Wood Frame Construction.”

 

[jayrod12]

I do not believe that the type of cladding over the sheathing matters. It's essentially saying if you don't have wall sheathing, then you must provide another method of lateral load resistance, I.e. bracing or moment frames.

 

[canwesteng]

Panel type cladding OR plywood sheating/etc

Stucco is fine on top of the sheathing.

 

[CANeng11]

Ok that makes sense. Is there any additional requirements like support behind all the plywood panel edges?

 

[atrizzy]

CANeng11, refer to the wood design manual for specified strengths of blocked/unblocked plywood shear walls.

 

[jayrod12]

Depending on the situation there is no requirement for blocking at shear wall panel edges. For older homes but new enough to have used plywood or osb I rarely see blocking because generally speaking the demand on the shearwalls was low enough to justify unblocked shear walls. On the newer homes with tons of large windows, blocked shearwalls might be required.

Can I ask what your application is to be asking these questions? New design? Retrofit? Re-cladding?

 

[Satya91]

Be Careful where you want to use the blocking for shearwalls, in some situations where you have a long narrow house with windows on the narrow side, your shear demand for the shear walls is quite high and you require blocking, see the shear wall selection table notes, check for OSB sheathing, if you can get away otherwise go for plywood sheathing.
Basically blocking is provided to prevent panel buckling due to high shear demand for nail spacing upto 75mm and for nail spacing 50mm use (2)2x stud wall and blocking.
Though the edge nailing defines the shear wall capacity, check the shear wall sill nailing and sill bolting to concrete wall connection capacity and the minimum of this is your shear wall capacity!