I am trying to put clapboards (FJ cedar) on a small wall. Nailing them
without causing splits seems to be beyond my skill level. (Using Maze
STORMGUARD nails. Face-nailing above the lap. Not trying to set them.
The problem seems to be just that my last hammer blow is more than the
unsupported wood can take. Alas.)

So, I'm thinking to cut a rabbet along the bottom edge of the
clapboards, so they can lay flat instead of bridging. Is there a reason
not to do this?

Thanks.