Repairing Decks and Railings | Family HandymanYou usually don't have to replace an entire board in deck repair work. Just make sure to cut out a piece that spans at least three joists. The remainder should be at least that long. And don't hesitate to cut out a little extra to keep adjacent decking joints staggered for better appearance. The most difficult part of this deck repair task is cutting out the damaged section cleanly. Don't try to cut directly over a joist. Instead, cut to one side and screw on a cleat to support the new decking.