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sill plate eccentric loading

JLSE

Structural
Oct 2, 2018
62
Is there any reason why putting the shear wall sheathing on the inside face of an exterior wall is not acceptable, or requires additional consideration?
Seems to me that the sheathing nailed to the inside face of the sill plate creates an eccentric loading condition, if the sill is then nailed to the band joist.
I havent found any code section it violates....
 
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My concern would be where is the stud wall relative to the foundation? Is this a concrete stemwall that can create a lip for water to collect and then move into the structure? Putting the sheathing on the outside usually provides the waterproofing we want and prevents water build up at the base of the wall.

Where are anchor bolts positioned? Can the wall be shifted to meet architectural plans and accommodate offset anchor bolts? Is there sufficient room to position the washers appropriately?
 
JLSE said:
Seems to me that the sheathing nailed to the inside face of the sill plate creates an eccentric loading condition if the sill is then nailed to the band joist

Not sure I agree. What is the load path? we have two (sometimes three, if perforated) forces that are resolved by the shear wall. The first is overturning, which is resolved by the tension/compression elements and hold downs at end of shear wall. The second is in-plane shear. That in-plane shear doesn't develop eccentricity because we only have typically have a single line of connectors, and the eccentricity is very low compared to the stiffness of the system and connection. Are you seeing the system differently?
 
So, the water issue is not a concern. there is insulated sheathing out the outside face.

The AB comment is related, because there is language in the code about the washer plate being within 1/2in of the wall sheathing for AB's... that was written due to eccentricity concerns in the testing, I think.

The in-pane shear attached to the inside face of the sill plate, travels through the width of the plate (5.5in) to exit into the band joist through sill nailing. So there is a 5in eccentricity.... which the code touches on for AB but not sill nailing. And with cyclic motion, causing nail withdrawal already, Id think the added eccentricity is an issue for consideration... it wasnt tested that way... but maybe it seems negligible to some.

Id think it depends on the wall length and shear demand, whether or not it was negligible.

But I am looking for some documentation on it....
 
Plate washers required within 1/2" of the sheathed edge is to limit cross grain bending in the sill plate around the washers, which will cause the plate to fail and increase drift, reduce shearwall stiffness and capacity, etc.

But I am looking for some documentation on it

See section 4.3.6.2 of SDPWS.
 
You're right, there is eccentricity between the sheathing nails to the sill plate and the sill plate nails to the rim board. I'd not be inclined to worry about it though. It's not as though there aren't eccentricities of similar magnitudes floating around numerous other common details. Presumably there are some nails connecting the sill plate to the adjacent framing that can be used nominally to resolve the eccentricity.
 

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