When strips are required, they must be installed VERTICALLY and nailed into wall studs, 16 in (405 mm) O.C., over the full height of the wall.
How do you nail LP Smartside panels?
https://www.youtube.com/watch?v=UtxYIcEVdGQ
What screws to use for LP smart siding?
Use minimum 8d (0.113 inch diameter shank), hot-dipped galvanized (ASTM A153 or equal) nails with a 0.270 inch diameter head for 38 Series and 76 Series panels when fastening to wood framing. Do not use electroplated fasteners.
What size nails should I use for siding?
Nail Length Ideally, you should space the nails so that each one penetrates a stud; 8d nails, which are 2 1/2-inches long, are suitable for most siding materials. It isn't always possible to nail into studs, especially when you're installing shake siding.