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Re: wood framing question

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-----Original Message-----
From: Kathleen A. O'Brien <wildwoman1(--nospam--at)compuserve.com>
To: INTERNET:seaoc(--nospam--at)seaoc.org <seaoc(--nospam--at)seaoc.org>
Date: Sunday, December 21, 1997 6:35 PM
Subject: wood framing question
>Seriously, though, I think it would depend on how you plan to connect them
>together. With a  double plate, you can connect the two pieces using
>standard length nails, but with a triple plate you would run into
>embendment length problems with a standard nail. Possibly lag screw would
>work. Or through bolts.
>
>Kate O'Brien, P.E.


I might be missing the point, but what is the difference if the spliced
chord is the top two plates or the bottom two? The assumption is that the
bottom two plates are not doing the job and the contractor does not want to
use straps to mend the discontinuity.
The purpose of the double top plate is simply to create a continuous tension
drag connection with a minimum force equivalent to the code required 4'-0"
lap splice and the capacity of the 16d nails at each side of the splice (I
don't have the code in front of me and don't remember the spacing or number
of nails required).  Therefore, it does not seem to matter where the lap
splice occurs as long as it occurs in at least two members, one member with
mechanical strap connectors (although code prohibits this for bearing wall
conditions) or by way of a header or beam that interupts the plate and
requires straping at each side to maintain the drag.
Therefore, what Kate refers to seems unnecessary - simply forget the bottom
plate and work with the top two plates to create the chord.
Finally, the shear transfer starts at the diaphragm, to the blocking to the
upper plate (the added 2x) and then into the boundary nailing of the shear
panel, studs and sole plate, the anchor bolts and holddowns for uplift
control - culminating at the foundation for anchorage. (Reminds me of the
old Toe bones connected to the ..... song.)
The load path is maintained and the chord can develop the minimum required
code force.

Dennis Wish PE