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RE: Shear Transfer from roof diaphragms....

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Dan,

> The Simpson A35 and LTP4 connectors look good if end blocking is present,
> but I don't believe that continuous end blocking will work due to attic
> ventilation requirements.

Try blocking every other truss space, 2 out of 3, 1 out of 3, whatever works
with your lateral loading at the top plate; i.e. loading from the diaphragm
is xx #/ft, you want to use 8d @ 4" oc capable of yy #/nail and your Simpson
connection from the blocking to the top plate is good for zz # each.  I have
also seen pictures of blocking with holes in it to allow ventilation, maybe
that would work for your application.

> If the distance above the top plate is 18" and
> the eave height is 11", what Simpson connector is available to transfer
> loads out of the roof diaphragm perpendicular to the roof truss?

Typically you would not transfer the load out of the diaphragm with a
connector.  You would use the connector to prevent "roll over" of the
trusses.  Look through your Simpson catalog, almost all of their standard
truss to top plate connectors have allowable lateral loads listed.  The H10
is real good (and $$).  A better source of information than the standard
Simpson catalog is their "High Wind" catalog.  Whichever you decide to look
at, read the general notes and be sure to check combined loading (unity
equation).  The one problem I see with you condition is that the 18" heel
dimension creates a pretty big eccentricity.  I would prob detail the
trusses with a boxed end heel and detail the top chord to extend past the
plate.  This way you could extend your sheathing up the side of the truss
and then build the soffits just like you would with rafter tails.  I do this
quite often when the architect(s) create offsets in the building perimeter
without creating a hip or gable.


>
> Where is the IBC 2000 specific about minimum requirements for lateral
> support?

Look at Section 2308 for Conventional Light-Frame Construction, specifically
2308.2, 2308.3, 2308.4, and 2308.9.3.  If you are not meeting the
prescriptive design of 2308, look at Section 2305.

> Also, is it common to have roof trusses at 24" o.c. and wall studs at 16"
> o.c.?  How is the double top plate analyzed for this situation?

Determine your maximum truss reaction, assume the trusses acting at 8" from
a stud and check flatwise bending of the double plate.  I doubt you will
have a problem.


bks


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