Chimney crown, Chase cover and chimney cap – Your first line of defense


While you’re putting your feet up and feeling the warmth of your fireplace, your chimney takes the brunt constantly belching out smoke and contaminants given off by combustion. You should contemplate this and know that it’s important to keep the essential parts of your chimney clean and safe. A good way to start is by keeping stuff out. This includes water, animals, and debris. These 3 essential parts of your chimney work together to do just that. Your chimney crown, chase cover, and chimney cap make up your first line a defense.


The chimney crown the top level of the chimney. That layer of mortar or cement sits right on top of the top layer of brick. Its the first line of defense against water. When properly installed the sloped surface edge diverts most of the water away from the chimney.

Being that the crown is right out there on top of the house it is completely exposed to the elements. Mother nature can cause cracks to develop on the crown. This allows water to seep behind the bricks inside the chimney. It is important to detect crown damage quickly and repair it. Otherwise, the masonry will begin to soften, and decay and spalling will occur and break off the chimney.  The crown seals most of the chimney, but the flue is still exposed.  Having a crown alone is not enough to keep all water and debris out of the chimney.


The chase cover is a steel or aluminum square or rectangle-shaped cap that fits snugly on top of the chase to help protect it from water damage. Right over the crown. Covers are prone to rusting especially in coastal areas, they need to be inspected regularly. They usually constructed of steel or aluminum


The structural housing between the roof line and the chimney crown is the chase. The chase directs smoke and sparks up away from the house. Depending on your home construction, the chase may be built with brick, wood, vinyl, or metal siding.


The chimney cap prevents water, birds, small animals, and debris from getting inside the flue. It’s mounted over the crown and is usually stainless steel. It has a mesh that let’s smoke out but prevents debris, animals, and water from getting in.

Without a cap, your flue and fireplace are exposed to external elements. That’s the inside of your chimney. Water causes masonry to decay and also can cause rust of important internal metal components. Dampers and smoke shelves can be very costly repairs. Creatures and other debris can clog the flue. Clogs prevent the dangerous fumes from burning the fireplace from exiting the house. This can put you and your family at risk of dangerously high levels of smoke and carbon monoxide.

Another danger is burning embers from the fireplace can be sucked through the chimney and land on your roof and start a fire. A downdraft can force open fireplace doors pushing smoke, soot, and ash into the house.

Have your chimney cap, crown, and chase cover inspected annually. If it needs repair, do so! 1800 Chimney technicians have certified chimney sweeps.