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RE: Wood - Lateral columns and knee braces (kickers)

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Dennis,
 
Maybe you could consider using something other than bolts at the brace
connections to increase the effectiveness of the braces, and the actual
stiffness of the frame.  We developed a new hex head 1/4" wood screw,
originally for our holdowns, but it seems that each day we are getting
reports of new uses for it.  The advantage over bolts is that there is very
little initial slip before the load is resisted because predrilling is
generally not required (it has a built in drilling tip).  It is made out
grade 5 steel, so the heads never twist off during installation.  Also, it
is ICBO (#5268) and LARR (#25281) rated, comes in varying lengths, and has
very good load capacity.  Our web site, www.strongtie.com
<http://www.strongtie.com> , has limited information under 'New Products',
and 'Nails" (more detailed information is available).  Depending on the
geometry of the connections, these fasteners could work very well for you. 
I'm really hesitant about 'advertising' in this forum, but this new type of
connector works extremely well and could be a big help to wood designers in
many situations.  Please contact me personally if you would like more
information
 
Sincerely,
Steve Pryor, SE
Simpson Strongtie
spryor(--nospam--at)strongtie.com <mailto:spryor(--nospam--at)strongtie.com> 

-----Original Message-----
From: Dennis S. Wish PE [mailto:wish(--nospam--at)cwia.com]
Sent: Thursday, September 03, 1998 12:02 AM
To: SEA International List
Subject: Wood - Lateral columns and knee braces (kickers)


I should know the answer to this one by now, but I think it has to do with
degree.
I am designing a Patio Trellis which is supported by four 6x6 DF #1 columns
at the unsupported edge. The shear on the supported edge is distributed into
a long shear wall and therefore no problem.
The columns are 10'-6" from the face of the wall.
I have designed the lateral being extremely conservative. I distributed 30%
of the weight of the structure (12 psf) into four columns. This amounted to
177 lbs per columns at 8' above the slab.
The moment at the base of the columns would be approximately, 1420 ft-lbs.
 
I don't want to embed wood into concrete and decided to create a pad footing
with a pedestal set six inches above the top of finished slab. I intended to
place a TS6x6x1/4" sleeve into the foundation and slip the wood column into
place. This way the wood can develope moment without failing relative to the
direction of grain.
 
This is a rather costly solution for a remodel. I wanted to get an opinion
about the use of bolted knee braces where the lateral load is relativly
small. The approach is to use a 2X6 on each face of the column bolted
through and connected to the beam which is a 6x8 DF #1. The connection of
the column to beam is done with conventional Simpson CC66's (ECC66 at each
end column).
 
I have not modeled this, but wanted to get a second opinion before investing
the time.
 
BTW, the top of the trellis is simply 4x10's @ 32" o/c with 2x2's at 12" o/c
above that.
 
I need to finish this tomorrow, so if anyone has an opinion, please let me
know as soon as you can.
 
Thanks for the help
Dennis Wish PE