how to make a chimney cap
Instructions. Measure the top of the chimney and the length, width and height of the flue. Build the bottom of the mold out of Â¾-inch plywood. Take the measurements of the top of the chimney and add 2 inches so the cap will overhang the chimney by 2 inches on all sides.Cut the plywood to that measurement by using a table saw or circular saw. Create the cutout for the flue.ake the measurements of the top of the chimney and add 2 inches so the cap will overhang the chimney by 2 inches on all sides. Cut the plywood to that measurement by using a table saw or circular saw. Create the cutout for the flue.