Thoughts on the best way to handle bevel siding expansion issues?

I've always stuck with the single nail method for cedar bevel siding. If you aim about an inch or an inch and a quarter up from the bottom edge, you just barely clear the top of the course underneath. That gives the wood enough room to breathe. I’ve seen guys use 2-inch Maze stainless ring shanks and double-nail, but three years later the siding looks like a jigsaw puzzle of horizontal splits becasue the boards couldn't move during the winter freeze.

The cupping argument is usually a red herring. Most of the time, if the boards are curling, it’s because someone skipped back-priming or used wet lumber from a bad batch at the yard. I’d much rather see a tiny bit of lift at the bottom than a ruined board that needs a full replacement. On my last house wrap, we made sure to leave a small gap at the corner boards and let the single nail do its job. It’s about managing the moisture and the expansion, not forcing the wood into submission. It’s wild that it turned into a physical fight, but honestly, I wouldn't want to work for a foreman who insists on double-nailing bevel. That’s just asking for a callback.

I honestly think the single nail crowd ignores how much modern lumber quality has tanked. If you’re working with clear heart cedar, sure, one nail works. But most of the stuff we get from the local yard these days is so unstable that single nailing just leads to massive cupping within two seasons. I’ve gone back to jobs where the bottom edge is kicked out half an inch becasue the wood just didn't have the structural integrity to hold its shape. On my last few builds, we’ve been double nailing using 6d stainless ring-shanks, but the trick is all in the prep. We back-prime every single board with a high-quality oil-based primer like Zinsser Cover-Stain before it goes up. If you seal the back, you’re cutting down that moisture movement significantly. We also make sure we’re hitting the studs every 16 inches on center instead of just relying on the sheathing. It’s a lot more labor, but I’d rather deal with the potential for a small check than a client calling me because their house looks like a Pringles can.

Back when we didn't have these fancy cordless guns, we used a story pole and hand-drove 6d galvanized casing nails. If you're worried about boards walking, you're likely not overlapping enugh. I always liked a full 1-1/2 inch lap. That extra half-inch of coverage keeps the board pinned better than a second nail ever whould.

And for the love of Pete, if you aren't pre-drilling ends near the corners, you're hacks. I don't care how many nails you put in the field; if the ends split, the wall looks like garbage. The foreman's an idiot for fighting over it, but the homeowner did you a favor. Get a crew that knows how to swing a hammer.

While the debate typically centers on nail placement, one must consider the specific metallurgy of the fasteners becuase using anything less than 316-grade stainless steel in a coastal enviornment—or even 304 in temperate zones—is essentially a countdown to tannin streaking and structural failure regardless of wheather you're pinning the top or bottom of the lap. I’ve found that the real culprit behind the cupping often attributed to single-nailing is actualy the omission of a proper rainscreen system; if you create a dedicated 1/4-inch drainage plane behind the bevel boards, the atmospheric pressure equalizes and the moisture gradient across the board's cross-section remains stable enough that a single 6d ring-shank fastener provides more than adequate retention without the catastrophic splitting risks associated with dual-fastener constraint.