Chimneys are not just straight columns of brick; instead, these complex structures have a number of different components that work together to help your fireplace burn and vent safely and efficiently. One of these important chimney components that is rarely acknowledged is the chimney crown.
What is a chimney crown?
A chimney crown sits on top of the chimney much in the same way a real crown sits on the head of a king or queen. Your chimney crown, however, has much more than just a decorative function. These large slabs are typically made of concrete and are used to protect and cover the top of the chimney structure around the flue. Chimney crowns are an important component of protecting your chimney against water entry as well as protecting the masonry of the chimney.
Because of their location, chimney crowns often bear the brunt of the elements. In order to last longer, it is important that they are built using the right materials; good chimney crowns should be made of concrete, not masonry, as the direct exposure to moisture can cause masonry chimney crowns to quickly deteriorate.
Chimney crowns should also not be completely flat. Chimney crowns built with a slight dome or slope are better than those that are completely flat as it prevents moisture from building up and sitting directly on the crown. Lastly, chimney crowns should have a lip or overhang that goes several inches beyond the chimney. Known as a kerf, these edges prevent moisture from flowing straight from the chimney crown onto the masonry of the chimney. This can help protect the chimney structure are water from rain and snow flow onto the roof instead.
Chimney crown damage and repair
Your chimney crown can be damaged even if the rest of your fireplace system is still working well; because of its location, chimney crown damage is often only spotted during chimney sweepings and inspections. Even if it seems like your fireplace is still burning well, chimney crowns should still be repaired as soon as damage is found.
Chimney crowns are particularly prone to damage and deterioration caused by the elements. Their location at the top of the chimney structure and constant exposure to moisture, direct sun, and the ups and downs
of outdoor temperatures can cause them to rapidly deteriorate if damaged.
There are several ways to repair damaged chimney crowns. If the damage is minor, such as small hairline cracks, waterproof sealant can be applied to the chimney crown. These sealants protect it against moisture and stop the deterioration of the crown while also preventing future damage from occurring. More extensive chimney crown damage may require more intensive repairs or a complete crown rebuild.
While many homeowners do not understand what it is, the chimney crown plays an important role in protecting your chimney system from damage from the elements. When built using the right materials and inspected every year, your chimney crown can last for years to come. For more information about the importance of chimney crowns or to have your chimney crown repaired, contact Mountain Man Fireplace & Chimney today!