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In a message dated 97-07-29 09:15:10 EDT, you write:

<< << Unsupported height is 24'-6" to top of ledger, TJI
  roof, not panelized. >>
 
 Mark -
 
 For my own curiosity, how are you making your out-of-plane connection to the
 TJI's now that the "standard" connection seems to be a pair of horizontal
 holddowns to a 4x member to satisfy the latest LA City requirements?  What
 are you doing at the parallel framing condition?
 
 <<I will assume this was not intended as a jab>>
 
 Definitely no jab intended.
 
 Good luck,
 
 Bruce Resnick
  >>

Bruce

The out-of-plane connection we have successfully used to TJI's is a pair of
holdowns each side of the TJI web which has been reinforced with a solid web
stiffener each side of the web.  The web stiffener is usually flush to the
outside edge of the top and bottom chords.  The stiffener is attached with
glue (APA approved glue or glue used by joist manufacturer) and screwed
through the TJI web into the stiffener on the opposite side.  The screws from
both sides provide a clamping force to provide better bonding between the web
and web stiffeners.   

The length of the web stiffener  we us is about 36" and is the full depth of
 the joist web with the first holdown anchor bolt being 12" minimum from the
end of the TJI.  The shear transfer is from bearing of the bolts on the wood
and then thru the glue (primarily) and screws to the joist web.  We have used
50 psi for the glue bond design value (plywood rolling shear is around 75
psi) and require that the glue be placed uniformly over the entire surface of
the web stiffener.  The glue easily develops the required shear transfer for
 the holdown forces, but you could provide all the shear transfer in screws
if you wanted to.  Typically we use an HD5 (not HD5A) each side of the truss,
 unless forces require larger holdown sizes.  

The web stiffeners can be shop installed if required (possibly only one end
shop installed if the other end is to run wild, contractor cordination
problem).  We have also done a similar approach on gang nail trusses where we
thickened the end of the top chords by screwing and gluing side pieces for
the holdown anchorages.  We have also used this detail on one OSHPD job.

When the joist is parallel to the wall, we use a tie rod threaded through a
hole in the TJI webs (reinforced with web stiffeners) with 2x blocking tight
against each side of the tie rod .  The blocking is nailed to the plywood
sheathing using 10d at 4"o.c and attached to the web siffeners with A35's.
 At the end of the tie rod we have a bearing plate which bears on a web
stiffener attached to the web of the TJI and is big enough to overlap the 2x
blocking each side of the tie rod on the opposite side of the joist.  The
wall connection is a threaded anchor bolt and coupler to the tie rod   As the
wall tries to pull away the tie rod goes into tension, putting bearing on the
blocking which is then transferred shear through nailing to the diaphragm. 

The depth of the tie rod into the diaphragm depends on the tie rod force and
using 10d nails at 4"o.c. through the plywood to the blocking for shear
transfer.  The tie rods are typically spaced at 4 to 8 foot on center along
the wall length and usually extend from  4 to 12 feet into the diaphragm
depending upon loading.  The only problem we have had with this detail is the
framer placing all the joist before threading the tie rod through the joist
web, but this is coordination problem.


Michael Cochran
BCASE1356(--nospam--at)aol.com