makes issues of the past fuzzy so here is what I recall:
There is a difference in shear capacity of box nails and commons. Common nails,
if I recall, have a thicker shank and larger head area which contributes to the
increase shear capacity as noted in the UBC nail capacity
vaguely remember the testing done by Ficcadenti and my memory recalls that it
was done prior to the publication of the SEAOSC standards for Cyclic testing
which would have made Ficcadenti's cyclic tests
Although this is a rumor, it was my understanding from other sources that
Ficcadenti's results, like the paper he wrote about eccentric blocking for shear
transfer, was done as an expert witness representing one of the sides of the
argument. This makes the results questionable. As I recall (and again this is
only from memory and should be verified rather than taken as fact) Ficcadenti's
paper on eccentric blocking which was published by SEAOC in "Proceedings" (the
SEAOC Annual Publication) was published without review or comment. It created
some stir as to how easy it was for an opinion paper to be published so as to
gain credibility in the professional community. The wood committee chairman at
the time issued a disclaimer indicating that the paper did not represent the
opinion of SEAOSC or the Wood Committee members.
would tend to base my opinions on the difference between Box nails and Commons
from the technical documents produced by APA, which was rather extensive. The
City of Los Angeles required a reduction of shear by 15% if box nails were used
in lieu of Commons. While it is true that Box nails were used at one time in
nail guns, it is my understanding that Commons have been available for nailing
guns for some time. While shank diameter is important in bending and shear
strength of the nail, you can't neglect the surface area of the head of the nail
as this will reduce pull-though and crushing of the panel
with APA on their studies done with Common verses Box nails. I believe it is
pretty intensive and should help you.
S Wish, PE
-----Original Message----- From: RShreenan(--nospam--at)aol.com
[mailto:RShreenan(--nospam--at)aol.com] Sent: Sunday, May 20, 2001 4:31
PM To: seaint(--nospam--at)seaint.org Subject: Plywood shear panels /
structural intellectuals and sport fans:
Is it reasonable to assume
that box nails perform as well as common nails in plywood shear panels
within the deflection limits required by the Uniform Building Codes
prior to 1997 (.005h)? Has there been any cyclic testing done
recently in that regard? I have the test results done by Seb
Ficcadenti and there does not appear to be an appreciable difference but
there seems to be a difference of opinion amongst structural engineers as
to whether the proper test protocol was used in the testing procedure.
I was also told by many that the SEAOC did not accept the results as
being valid, but I don't know for what reason.
It seems that 8-10
years ago and prior most wood framed residential projects with plywood
shear walls and diaphragms were nailed with gun nails that were box nails.
I would like your opinions on this issue or any sources
of information on documented cyclic test results on plywood shear panels
nailed with box nails.