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california redwood association

How long do siding nails have to be?

The CRA recommends and the Uniform Building Code now requires that the siding nails be of sufficient length to penetrate 1-1/2 inches into combined solid wood sheathing and framing. So, for example 1/2x6 plain bevel siding over 1/2-inch plywood sheathing and 2x4 framing would require a 2-inch long or 6d nail.

Remember that rigid foam sheathing has no nail-holding power, so these installations require a longer nail. For example, 1x8 T&G siding over 1-inch rigid foam sheathing, 1/2-inch plywood and 2x6 framing would require a 3-1/4-inch or 12d nail.

  n e x t 
rabbeted bevel siding: expansion gap