Whether you aspire to recreate the feel of the Victorian era or want to finish your chimney with the clean, simple lines of a classic chimney pot, Darden Building Materials can help.
In order to select a chimney pot that will function properly, it is important to consider the top opening in relation to the fireplace opening, and the base dimension of the chimney pot in relation to the flue it is covering.
The top opening of the pot should be in ratio to the fireplace opening. The chimney pot opening is often smaller than the effective area of the flue liner in order to reduce the effect of wind on the draft. Flue area is typically about 1/10 the fireplace opening area for square flues and about 1/12 for round flues.
For chimney pots, this ratio is often reduced to 1/15 - 1/20. The base inside dimension should be nearly as large as or larger than the largest dimension of the flue the pot is being installed on. The chimney pot should not impinge on the effective area by more than 3/4 of an inch. Many other factors, such as fireplace chimney construction and house air pressure can affect proper chimney operation.