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RE: Out of Plane Wall Anchorage

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1. Your bldg must not be in zone 4 if your are using single embedded nail
straps @ 8ft o.c. as your wall anchor. Make sure you hook the end around the
re-bar in the wall. The section applies in Zones 3 & 4 only, so I'll assume
you are in Zone 3. It looks like Utah has zones 1, 2B, and 3.

2. You could do a calc. of nails in single shear w/ metal side plates and
prove the connection works. Use the 1.5 inch penetration and reduce the
allowable accordingly per NDS.

3. As far as the 2.5" requirement, If your building official will accept it,
you could check the axial stress in the top chord/flange in tension at 1.0
Fp. Since it is LVL, I'm sure it will easily take the load if a scrawny
strap will take the wall load.

4. The TrusJoist/Macmillan catalog I have shows one of those diagonal twisty
strap thingies bolted to the web through a web spacer block. I would not
suggest single sided connections however due to eccentricty. You could also
use simpson hd's or even better Zone 4 CT's ea. side bolted through the web
w/ spacer blocks.

5. Have you considered 4x's for your purlins or Steel OWSJ's? You are in
Utah, so Vulcraft is right down/up the road from you.

6. As far as the member size goes with a smaller force . . . The force
increase from the 1997UBC is still larger at 0.85 Fp than the 1994UBC value.

To steal from the same humor as James Bela . . . May the force (or
displacement) be with you, always.

Gerard Madden, P.E.
Civil Engineer, Associate
CRJ Associates, Inc.
email: gerardm(--nospam--at)
tel: 650.324.0691
fax: 650.324.0927

> -----Original Message-----
> From:	Jake Watson [SMTP:jwatson(--nospam--at)]
> Sent:	Thursday, December 02, 1999 5:37 PM
> To:	seaint(--nospam--at)
> Subject:	Out of Plane Wall Anchorage
> I have a question regarding wood diaphragm anchorage to masonry/concrete
> walls. Section 1633.2.8.1 (Out-of-Plane wall anchorage to flexible
> diaphragms) item 5 reads as follows:
> 5.	The strength design forces for wood elements of the wall anchorage
> system shall be 0.85 time the force otherwise required by this section
> and these wood elements shall have a minimum actual net thickness of
> 2-1/2".
> We are attaching a tilt-up wall panel to a wood floor and roof system. 
> I take this to mean that I need a minimum of 2-1/2" nail penetration
> into whatever I nail to.  I if nail a joist, I need 2-1/2" penetration,
> same thing for a truss.  I also understand the need to prevent pullout.
> So here's the question, is there a way around this provision that makes
> sense. I want to follow the code, but manufacturing trusses out of 3x
> doesn't make sense.  And only the largest TJI's will meet the
> requirement.  Suggestions anyone?
> P.S. Why increase the member size while decreasing the force????
> Jake Watson E.I.T.
> Salt Lake City, UT