A chimney cap or crown acts as a ceiling. The slope of the cover allows the water to flow away from the fireplace. When water seeps into the structure of the fireplace, can cause cracks in the masonry. Installing a chimney cap on will help prevent damage caused by water. These caps experience a lot of stress due to changes in temperature of the chimney and the pipe. Inspect annually for cracks and damage.
Instructions
- Measure the top of the chimney and the length, width and height of the tube.
- Build bottom of pan with plywood 3/4 inch (19 mm). Measure to the top of the chimney and add 2 inches (5.08 cm) to cover protrude 2 inches (5.08 cm) on each side of the fireplace. Using circular table or saw or plywood cut to the measure.
- Make the fireplace opening. In the center of the plywood draw the outline of the cutout to the tube by using the measures; thereof add ¾ inch (19 mm) on each side of the line to leave the space between the tube and cover. Cut on this line to the exhaust pipe.
- Cut the pieces to form the tube outlet. Cut four pieces of plywood 1/2 inch (12.7 mm) long by the width of the tube. These parts fixed to the bottom of the mold to form the sides of the cutout. Place each piece against the inside of the cut so they are 4 ¾ inches (12.07 cm) high. Adjust screw bottom side to the bottom of the mold. Fix parts to the ends of the piece next to it to create a small box with no bottom and no ceiling in the center of the mold.
- Cut the plywood of ½ inch (12.7 mm) to the sides of the mold. Cut four side pieces 3 ½ inches (9 cm) high by the width of the fireplace. Attach each piece to the sides of the bottom mold. Place the side pieces up so that they are 3½ inches (9 cm) tall and screw bottoms at the bottom of the mold. Screw the ends of the lateral ends of the side beside them; this will create a box with a smaller box without background in the center.
- Create a drip edge around the top wooden pegs sticking 3/8 inch (9.5 mm) in the bottom of the box to 1 inch (2.54 cm) away from sides of pan.
- Covering the mold with vegetable oil to prevent the mixture sticking, Portland cement mixture according to the manufacturer’s instructions, Pour the concrete into the mold. Alisa cement with a wooden board. Let the cement to set per the manufacturer’s recommendations. Cure the cement spraying with water every day for a week.
Tips & Warnings
- You can replace the hard mortar mixture of Portland cement
- The cement may cause irritation to the eyes, throat and skin. When working with the used gloves and goggles and cover your mouth.