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Thickened footings under interior braced walls (Was: RE Hardy Frames)

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Dennis,

Our local building inspector called us one day because a contractor's plans
showed  the sill for an interior braced wall shot down onto a 3-12 inch
slab.  The inspector wanted help finding something in the code that
prohibited this.  Since I like to stay away from the Conventional Light
Frame section, I could not immediately point to something, but he ended up
finding it himself.

In the very last paragraph of UBC/CBC Section 2320.11.3, it states:  "Sills
shall be bolted to the foundation or slab in accordance with Section
1806.6."    Section 1806.6 calls for anchor bolts "embedded at least 7
inches into the concrete or masonry".   This was enough for our inspector to
require footings under interior braced walls.  But he was actually TRYING to
find a way to do that--if you have someone trying to find a way NOT to
require it, they could latch onto the "foundation OR SLAB" phrase;  but
there's still the 7-inch required embedment, and I hope any inspector knows
the 3-inch clearance requirement from steel to soil for concrete--that gets
at least a 10-inch "footing".     Which is probably sufficient for those
lame-O braced wall panels anyway.

Main problems I see with Hardy Frames, Strong-walls, Z-Walls, TJ-Shear
Panels,  Shear Max, etc.  are when people try to fit them into applications
where they need to be put on concrete pedestals, have a cripple wall built
on top of them, or some other such thing.  My upcoming book <advertising
mode on> (reserve your copy now at www.shearwalls.com) <ad mode off> has
several photos (taken elsewhere) of pre-fab bracing units placed on severely
spalled concrete curbs, shimmed with square washers, mis-used on second
floors, and "oops--we forgot to attach it to the top-plate" types of
installations.

Artificial shear walls have not infiltrated the construction market in my
corner of Calif. yet, so can't comment on what contractors prefer.

By the way, you state that  "the braced panels called out in the code
don't require resistance to uplift unless they are less than a 2:1 ratio".
Is this explicitly stated in the code?  My impression is that braced wall
panels can be used in walls up to 10 feet high (the limit for "conventional"
framing), which would be 2.5:1.   But like I said, I try not to become too
familiar with that code section....I don't want to find myself looking up in
a span table what I could calculate in 1/3 the time!

Thor



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