Many homes in the Kansas City area have masonry chimneys built with corbeled brick, and homeowners may need to parge their smoke chamber this summer. While your wood-burning fireplace was keeping your family warm and cozy in the winter, the smoke and fumes were passing through an area known as the smoke chamber as it travels up the flue to exit the chimney.
Due to its proximity to the firebox, the smoke chamber is a high-heat area. The stair-stepped design of corbeling can create problems for homeowners, highlighting the importance of annual chimney inspections, especially in older homes. That’s because the exposed jagged edges can allow moisture to pool on the brick surface, accelerating masonry deterioration. It also reduces airflow efficiency and results in the additional build-up of combustible deposits, increasing the risk of fire and exposure to carbon monoxide fumes. If smoke chamber defects are not corrected, the high heat can ignite the creosote and cause a chimney fire. Even a small chimney fire can spread to nearby combustible building materials and cause a house fire. According to the National Fire Protection Association (NFPA), excessive creosote in the chimney is the leading cause of residential structure fires.
What is Parging
Parging is the process of smoothing the jagged edges and repairing any masonry damage like cracks or gaps in the brick and mortar. We use Heatshield® to make smoke chamber repairs because the cerfractory sealant increases the chimney’s integrity while resisting moisture, corrosive gases, and the extreme temperatures of the smoke chamber. It is UL listed and tested to ASTM C-199 and can withstand temperatures of over 2,500°F. A smooth smoke chamber surface reduces the build-up of creosote and soot deposits in the smoke chamber and reduces fire risk. It also improves the airflow efficiency in the chimney, making it easier for smoke and dangerous gases to vent out of the home.
Does My Chimney Need to Be Parged?
Both NFPA guidelines and the International Residential Code (IRC) state that if the inside surface of the smoke chamber has corbeled masonry, it shall be parged smooth. However, it is difficult for homeowners to determine whether their chimney needs parging without a chimney inspection. The smoke chamber is one of the many parts of the chimney system checked during an annual inspection. If it has been more than two years since your last chimney inspection, we highly encourage scheduling a level 2 chimney inspection this summer, including a video scan of the interior surfaces. A video scan can spot minor cracks and other imperfections in the masonry that are more difficult to see with a visual inspection allowing repairs before they can cause more severe issues. When the Certified Chimney Sweep® observes corbeling in the smoke chamber, parging will be recommended to bring the fireplace and chimney into compliance with current building codes and to reduce the risk of fire and carbon monoxide exposure.