It has been said that if you got out into the rain without your hat on, your head will get wet! Pretty simple idea isn’t it… but you know what? As simple as it is, it is true.
Like a hat for your head, a chimney crown is a hat for your chimney. The purpose of the crown is to shed rain water from the top of the chimney and to keep it from entering into the chimney shell; keeping it dry. Let’s take a look at the different types of masonry crowns used widely today… ok?
Cement Wash – This is the most widely used crown for chimneys today. It consists of a cement grout that is applied to the top of the finished chimney masonry and slopes upward to the chimney flue liner.There are literally millions of these crowns in existence today and they can work very well initially. This crown is the easiest and cheapest to install but tend to be the first to first to crack and fail. Durability is usually from 1 – 5 years.Concrete Crown – Cast in place concrete crown are used less than the cement wash crowns but still seen frequently. This crown is installed by building a form over the top of the finished masonry of the chimney and filling it with concrete. Sometimes steel can be added for further durability. It too is slightly tapered to shed water and usually extends approx. 1” – 11/2” beyond the side of the masonry to form a drip edge.
More expensive than the cement crown wash the cast in place concrete crown can last very long depending on the quality of the concrete, the design and installation. Durability is usually from 20 – 30 years.
Cut Stone Crown – This is the most durable crown available in the world today. A piece of local stone, generally limestone is designed, cut and set on top of the finish chimney masonry to act as a crown. All of the oldest masonry chimneys in the world today will have cut stone crowns.
The stone will be cut to 11/2” – 4” thick depending on the architectural requirements. The length and width of the finished chimney are measured and an additional 3” – 4” is added to the cut stone to allow for a drip edge. Some of these stone crowns can get massive, weight several thousand pounds and may require a crane to set in place.
However when done properly these beautiful pieces can add a decorative architectural statement. As you may imagine stone crowns are the most expensive to construct due to the knowledgeable labor needed to measure and fabricate and the necessary equipment needed to install. However they will last for hundreds of years.
The simple chimney crown can be humble or grand depending on the whims and wishes of architects and building owners but regardless of how they look the function of the crown remains the same. Like a hat keeps your head dry, a chimney crown keeps the masonry on your chimney dry and should not be neglected.
