The necessary materials for a homemade burn barrel are a 55-gallon steel drum with one side open, a metal grate or a piece of heavy fencing, a piece of sheet metal and two concrete blocks. Select a location to place the burn barrel that has no trees or flammable materials nearby. Make sure the air that reaches this location doesn't flow in the direction of the house.
Use a handgun or a drill to make three or four holes in the bottom to prevent rainwater from accumulating. Drill a maximum of 20 holes for air circulation. Drilling more than 20 holes accelerates barrel rusting and causes burner failure.
Place the barrel with the open side up over the concrete blocks. Make sure the barrel edges are on the blocks and that there's enough open space underneath the barrel to allow air circulation and water drainage.
Use the metal grate or heavy fencing segment as a burn cover to prevent material from escaping during combustion.
Use the sheet metal as a cover while the barrel is not in use. The sheet metal acts as a rain cover that protects the barrel contents from getting wet and slows down barrel rusting.
Research local ordinances concerning open and outdoor burning before making a burn barrel. Don't burn large items. Separate the items to be burned and burn them one pile at a time.