To reduce wood splits, such as when building a deck, first drill pilot holes for the nails using a drill bit size about three-quarters the diameter of the nail. In a pinch, if you don’t have a bit you can chuck in one of the nails being used. Blunting the nail point will also help prevent splits, since a blunt nail will tear, rather than spread the wood fibers. An alternate method to avoid splitting the ends of boards is to allow an extra length to hang beyond the edge of the deck, do the nailing, then use a circular saw to trim off the ends.