Actually, I was sitting by waiting patiently for John
Rose to reply to this one. I was beginning to wonder if he was ever going to
reply - I had my doubts for some short moments, but, AS I KNEW HE WOULD
- John Rose came through. Thanks, John, for not letting us down and
for replying before I would had the chance to thoroughly embarrass
S. Wish PE
-----Original Message----- From: John Rose
[mailto:jrose36(--nospam--at)earthlink.net] Sent: Thursday, March 09, 2000 8:26
PM To: seaint(--nospam--at)seaint.org Subject: Re: horiz. diaph.
The traditional approach is to apply blocking
flatwise and adjust lateral load for sheathing nails based on actual vs.
required nail penetration (or refigure based on EYM in 1997 NDS). But
APA has a recent report (APA Report T98-22) which shows nail penetration based
on NDS EYM methodology can be reduced to 1.5" for 10d common nails, and 1.375"
for 8d common nails. This provision will be included in 2000 IBC for
shear wall and diaphragm tables. The 10d common short (diaphragm) nails
(0.148" dia. x 2-1/8" long) will provide the needed penetration with 15/32"
and 19/32" wood structural panel sheathing; actually, a 0.148" dia. x 2" nail
would work better with 15/32" sheathing. A caution, though - if you get a
lot of nails in 2x flat blocking, you may split the blocking. It might be
better to use 15 ga. or 14 ga. staples into 2x flat blocking; or if nails are
used, change to 3x or 4x blocking. John Rose/APA, Tacoma, WA
Mark Baker wrote:
If 2x4 blocking, laid flat is used for
blocking in a horiz. diaph., what reduction in shear capacity should be
applied? If there is such
a reduction, does it correspond to a shorter (10dx1.5") nail, nailed into
the 1.5" block dimension or the normal 10dx3" nail? Or, is blocking laid flat simply out of the