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Re: High-load plywood shear walls

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APA has published design info for plywood shear walls using wide-faced
framing and multiple lines of nails each edge. In this way it is possible to
mobilize much more of a plywood sheet's strength than with only one line of
edge fasteners. Allowables in excess of 1000 plf per face are available.
Plywood thickness likely is not what controls, rather the fasteners and what
they fasten into. Split-resistant backing at horiz interior edges would also
be nice.

Inquire of APA for particulars. Maybe John Rose will reply on the list.
Maybe the proponents of concentric hold-downs will have some tips too.

Do take good care of the external connections, bearings, anchorages, and
foundation stability concerns that are part of the system. Overturning
effects will be in big numbers. Possibly several anchored vertical "edge"
members at each edge, that are good columns for the height, will be needed.
I don't see how steel helps for boundary members, since it is hard to fasten
to with nails, and bolts in shear slip in their bolt holes and make the
rigidity go away. Those parts that lack good ductile overstrength or cause
rocking deflection should have some concession to the Omega factor included
in their design basis, so they can't give up or go wimpy before the shear
sheathing does.

Charles O. Greenlaw SE   Sacramento CA

At 06:03 PM 04/19/2000 -0700, you wrote:
>     What is the most anyone has ever calced for a plywood shearwall? Can I
use 3/4" plywood both sides and use values above the tables in the UBC?
Will I need 4x panel edge members?  
>     I have a 35'+ high wall and need to keep it as thin as possible.  Non
load bearing, interior shear wall.  I already plan on using LVL studs and
steel boundary members.  Don't want to use masonry.  Need to push the
limits, and suggestions?
>Jake Watson, E.I.T.
>Salt Lake City, UT