Walk across any wood deck, and you'll probably see a nailhead or two popped up above the surface. Popped nails aren't just unsightly; the protruding head can cut bare feet and cause a nasty fall if it catches a shoe heel. Pounding the nailhead down solves the problem temporarily, but the nail usually works itself back up again before long. To keep a popped nail down, first tap it below the surface with a hammer and nailset. Then drive a 3-inch-long decking screw alongside the nail, making sure that the screwhead overlaps the nailhead.