chases, exterior?

[rktect 1]

So, I was wondering what everybodys fast and hard rules are on these. I have a fireplace chimney chase shown on a plan. Mine shows dimensions of 30"x44"wide. Simply attached to the side of the house plywood. It is made of 2x4 @ 16" o.c. and plywood and extends from the bottom of the floor level (no support either by slab or cantilever) all the way through the roof about 15 feet tall.Just wondering what others allow in size for a chimney chase. Maybe there is even a code section somewhere but I haven't really found it.Sort of like this one but only 15 feet tall and no cantilever floor support.

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[Mr. Inspector]

R601.2 Requirements. Wall construction shall be capable of accommodating all loads imposed according to Section R301 and of transmitting the resulting loads to the supporting structural elements.

R1005.1 Listing. Factory-built chimneys shall be listed and labeled and shall be installed and terminated in accordance with the manufacturer's installation instructions.

R1005.5 Support. Where factory-built chimneys are supported by structural members, such as joists and rafters, those members shall be designed to support the additional load.

 

[TheCommish]

Ours they cantilever the floor out to support the weight of the chase walls and put a fire block in at the 2nd floor level, while keeping the wall sheathing in place up to the roof line

 

[fatboy]

Yeah, think I would have an issue with it, would require an engineers stamp on it. The whole thing is hanging of the shear of the nails to the framing, and the shear of the plywood. Don't think that falls into prescriptive codes.