nail laminating the multi-ply header
1) Since my lams are `true’ 2 inches thick … the 16d sinkers nails will not get quite enough penetration1 (to use the NDS Table value). I’ll either need to take a reduction, calculate the nail value with the reduced penetration length, or use a larger nail. Hmmmm. The 20d Common, of which I have a bunch, has a total length of 4 inches, which will give me 2 inches of penetration. I could call it good! … since it will give me all of what the 16d sinker would have given me with full penetration. The 2 inches of penetration is also enough to give me the full lateral value for the 20d nail (D = 0.192; 10D = 1.92, etc.). The lateral design value for the 20d Common is …185 lb (2018 NDS Table 12N).
2) Turns out I can use the NDS Yield Limit Equations (splitting hairs using the background equations for the NDS Table) and still get the `128’ even with the reduced penetration.
3) The calculated nailing schedule is for my specific situation. The IBC prescriptive requirement might no doubt accommodates (one way or another) more heavily loaded beams and headers.
I have a bunch of 20d Commons … I might just go ahead and use them. I have a heavy hammer – it will be fun.
ROAR!
1Use of the Table values requires that the nail penetrates at least 10D into the main member. If I use 16d sinkers, which are 3.25 inches long, and pound them flat to the lam face, the amount of penetration is 3.25 in. minus 2.00 in. gives 1.25 in. of penetration. The 16d sinker diameter is 0.148 in., so 10 times 0.148 is 1.48. At face value I should take a reduction of 1.25/1.48 = 0.84 … or 0.84 x 128 = 108 lb each nail. Turns out splitting hairs with the NDS Yield Limit Equations, and still get the `needed’ value. (Some day I’ll show you.)