Fireplace Chimney Chase

Chimney Chase – The area or structure around metal flue pipes. The chase is usually built with wood or steel studs with an exterior that can include brick/stone veneer or wood siding or stucco. Chimney – One or more passageways, vertical or nearly so for conveying flue gases from the appliance to the outside atmosphere …Aug 28, 2016, Pennsylvania Guild of Professional Chimney Sweeps, http://paguild.org/chimney-terms

OK, that’s the definition by the Pa. Guild but there’s much more to the story. Most of the time the chase is defined as the part of the chimney protruding above the roof line. As you can see, and I happen to agree, the above definition includes the lower part of the chimney as well. Therefore, I always consider the chimney chase as all the chimney visible on the outside of the house. As stated above, the chimney chase can be brick, stone, wood or stucco. Also a chimney can have multiple flues. Older buildings in England and some in the U.S. have multiple flues. These came about when buildings housed multiple residences, (flats, apartments) and each resident or family had their own fireplace.

The part if the chimney chase that is above the roof line serves several purposes. It is far enough above the roof to prevent embers from setting the roof afire. It moves smoke away from the home. The chimney cap prevents rain and debris from falling down the chimney as well as preventing birds and small animals from entering. The chimney chase that is above the roof line has to be located in a very specific and, I think, confusing way.

First, facing the rise of the roof, we must use our imagination to visualize a horizontal line through the chase to the point it touches the roof. This horizontal line, from the inside of the chase to the roof must be ten feet. The distance vertically, from our imaginary horizontal line up the inside face of the chase to the top of the chimney must be two feet. The distance vertically from the outside face of the chase at the roof line to the top of the chimney must be three feet. The top of the chimney is the level at which the flue exits the chimney. Confused? I still am. However, there are several good graphics to be viewed online if you search chimney chase.

As I have stated before, the original fireplaces evolved from an outside to an inside fire pit. Inside fire pits were vented through a simple hole in the roof. Hearths were invented for heating and cooking. Finally, when the hearth was moved to an exterior wall, the chimney developed. There were many variations of fire.places and stoves. Count Rumford invented a shallower fireplace and his designs are still used today. Ben Franklin invented the Franklin stove. Again, his design is still in use.

One last thing to clarify, and that is the smoke stack. To me, smokestacks are the giant chimneys one might see in an industrial area. They are used for various purposes. A flare is a way to get rid of unwanted material that has built up through the constant work flow of a particular industry. In the oil refining industry flaring is a method used to control pressure buildup in plant equipment. I am amazed every time I see a flare, especially at night. I guess the point here is that smoke stacks are completely different from residential chimneys and flues.

As usual, be sure to call your local chimney and fireplace experts for cleaning and maintenance. fireplaceflair.com