You hear a lot about your chimney liner, dampers, firebox, maybe even your chimney cap. But how often to you hear about your chimney crown? Sometimes people use the terms ‘chimney cap’ and ‘chimney crown’ interchangeably, but these two components of your chimney system are actually different. Some of the roles they play are similar, but they are two very different structures on your chimney.
What is a Chimney Crown?
The chimney crown is the top part of your masonry chimney. It is a concrete structure, and it is created to play a big part to keep precipitation out of your chimney. It covers the top of your chimney, and it goes out over the edge of the chimney itself slightly. The design is unique so that it is sloped downwards so that precipitation is directed away from the chimney, instead of hitting the roof. This is very important because if the precipitation is allowed to get into your chimney, it can cause major damage to the interior of your home as well as to the structure of the chimney.
Another construction error that affects the performance of your chimney crown is that it is not made of the proper material. It’s important that chimney crowns be constructed of a Portland cement mixture,and reinforced with mesh. Too often, chimney crowns are constructed of a mortar mix which isn’t designed to withstand the elements that a chimney crown must withstand.
The Proper Chimney Crown
Your chimney crown should project at least two inches over the edge of the chimney. If it’s less than this, it allows precipitation to fall too close to your chimney. This also weakens your chimney flashing and allows water to enter your chimney system. You’ll also need to ensure that the chimney crown is at least two inches thick in the thinnest part; three inches is even better. Remember, this is the area most exposed to the wind, rain, and other weather, so this is not the component to take shortcuts.
Call the People Who Know
If you’re worried about leaks or the condition of your chimney crown, give Jiminy Chimney Masonry and Repair a call at 847-893-0063. Our technicians are expertly trained to look for chimney crown issues. They are also knowledgeable about the necessary repairs needed for your chimney crown. We also understand proper construction techniques, so if you need a total chimney crown replacement, we can help!