Nails and Horizontal Shear
Nails and Horizontal Shear
(OP)
In the APA Table for Recommended Shear for Horizontal APA Panel Diaphragms ..., we are only allowed to specify 10d nails at adjoining panels if the framing is 3" nominal.
Does anybody use 3" nominal framing?
Are there alternatives?
Are there more current APA table?
Is there revised information on fasteners such as those with a ringed shank that may have greater pull-out values?
Any increase factors for fasteners applied with air guns?
Thank you!
Does anybody use 3" nominal framing?
Are there alternatives?
Are there more current APA table?
Is there revised information on fasteners such as those with a ringed shank that may have greater pull-out values?
Any increase factors for fasteners applied with air guns?
Thank you!






RE: Nails and Horizontal Shear
Correct me if I am wrong, but I do believe it is correct to interpet this requirement as 3" nominal in width, or 2 1/2". If you use a 2 x 4 flatwise, that gives you a 3 1/2" wide nailing surface. Similarly, I-joist products typically provide a nailing surface that is at least 2 1/2" wide.
Try contacting Trus Joist MacMillian.
No, APA does not currently provide an alternative to this requirement. Yes, using a different type of fastener would have some effect upon the panel's performance; however, remember that these tabulated values are based upon lab test results. Any variance from the parameters of these lab tests with the intent to obtain better design values could only be accepted if proven by another lab test. So, yes, go ahead and use wood screws, etc., but you cannot convince any plan checker that screws provide a better value than what's shown in the table for nails. (any way you look at it, you're "screwed" -- just kidding!)
Be careful in specifing the use of air guns for nail placement. Be sure that the air pressure in the gun is restricted such that the result is no more than if you used a conventional hand-held hammer. We do not want to allow the nail head to penetrate the top ply of the plywood any more than would occur with a hand-hammer.
Another thought: look into the actual size of the "10d nail" used in the nail gun -- it likely is not the same as the conventional 10d nail. However, it is often considered an acceptable substitute.
Enough said?
-Richard L. Flower, P. E.
RE: Nails and Horizontal Shear
In the case of trusses with 2X cords it is permissable to double up the cords, however, the nailing for the scab must be checked.
You may use 10D nails if the spacing is 4" o.c. ore further.
For more information on this see UBC97 Table 23-II-H page 2-287
RE: Nails and Horizontal Shear
How do you know the "proper nail is a 10D short (2 1/4")"?
Where is this stated?
Thank you!
RE: Nails and Horizontal Shear
Experience. A 10D common nail is 3" long and as such tends to split lumber regardless of 3X members. The code (IBC or UBC) requires 1 5/8" penetration into main members, given 5/8" sheathing a 2 1/4" nail provides the required penetration.
RE: Nails and Horizontal Shear
RE: Nails and Horizontal Shear
RE: Nails and Horizontal Shear
If panels edges occur on a doubled up member, and 10D nailing is specified, lets say @ 3" o.c., then the doubled up member would probably have to be nailed to each other somewhere close to the same schedule in order to keep them from pulling apart. This will most likely detroy the integrity of the two members. This amount of nailing is certainly not allowed by NSD.
3X members are specified to eleviate splitting of the member thereby keeping the integrity of the member.