Tired of large patio umbrellas tipping over? Add this simple addition to your deck or dock in several locations and you are set! Cut 45% angles on the ends of boards to fit into a corner. A short piece of heavy pvc pipe for the bottom. Drill large enough holes into the front of the obc for your drill bit to get into. Depending on your deck design you may have to place a block behind the pvc to bring it out level. Drill pilot holes into the back of the pvc for the screws to hold it in place.