Where power nails or nails with smaller diameters than that required by Table 9.23.3.4. are used to connect framing, the following equations can be used to determine the required spacing or required number of nails.
The maximum spacing can be reduced using the following equation: S = S x (D / D)² where Sadj = adjusted nail spacing ≥ 20 × nail diameter, Stable = nail spacing required by Table 9.23.3.4., Dred = smaller nail diameter than that required by Table 9.23.3.1., and Dtable = nail diameter required by Table 9.23.3.1.
The number of nails can be increased using the following equation: N = N x (D / D)² where Nadj = adjusted number of nails, Ntable = number of nails required by Table 9.23.3.4., Dtable = nail diameter required by Table 9.23.3.1., and Dred = smaller nail diameter than required by Table 9.23.3.1.
Note that nails should be spaced sufficiently far apart—preferably no less than 55 mm apart—to avoid splitting of framing lumber.