Return to index: [Subject] [Thread] [Date] [Author]

Re: nailing zones in plywood diaphragms

[Subject Prev][Subject Next][Thread Prev][Thread Next]
At 10:05 AM 4/27/99 -0700, you wrote:
>In many large diaphragms (i.e. tilt-ups) the nailing is divided into several
>zones with the nailing requirements increasing as it gets closer to the
>boundaries. My question is: 
>
>At the transition from one zone to another, what type of nailing is
>required? Should the edge nailing of plywood pieces that cross over the
>transition line be:
>
>1.	The "boundary edge nailing" as required for the more restrictive
>zone.
>2.	The Nailing required for "other panel edges" for the more
>restrictive zone
>3.	Other
>
>Please comment
>
>Thanks
>Ben Yousefi, S.E.
---------------------
        Here's a few comments, but not necessarily any answers

Are you designing or enforcing? That may be significant.

If you are designing, the cost of any extra nailing to cover any doubt is
too little to be concerned with. Put in plenty.

If diaphragm stiffness is important, to limit lateral period or drift, more
nails helps, and better than linearly. "Nail slip" is a big component of
total flexibility and drift. Less load per nail helps in a big way, and
raises ultimate strength too.

If you are enforcing, then as your questions are worded, what is "required"?

Required by you, or by some clearly standard custom (if any) or by the
diaphragm itself, supposing we can tell?  Why not pick the first of these
bases of "requirement", and require nailing the way you prefer? If I were
arguing with you, I would cave in quick and add nails until you were feeling
confident about it. 

ATC 7 is "Guidelines for the Design of Horizontal Wood Diaphragms". I
rediscovered it this morning, and it is old but pretty complete. I haven't
the patience to search it on these questions. I would rather add the nails.

Charles O. Greenlaw  SE   Sacramento CA