Up on the Housetop: Chimney Fundamentals

12.17.2021

Complicated chimney work has long been an architectural feature of high-end residential homes. The shape and size of a chimney are part function and part aesthetic, and the structure itself can accomplish multiple purposes. While most chimneys are used for venting fireplaces, others vent fuel-burning heating systems or accomplish purely design-driven purposes.  Below, a short primer on the fundamentals of chimneys.

In the United States, chimneys were originally built along a residence’s exterior and in the late 1790s were incorporated into interior walls. In colonial New England, moving the chimney to the center of the house and including multiple flues meant that fires could be lit in two or more rooms. These central fires would effectively heat the home’s center mass, thereby keeping the building warm for longer periods of time especially during cold winter months.

Chimneys were originally built along the exterior walls of a home until the late 1790s.

While chimneys have evolved, their scale and symmetry remain impactful design elements. For instance, homes built on the water tend to be long and linear due to height restrictions. Incorporating taller chimneys can introduce verticality to these structures, breaking up the line, introducing variation along the roofline, and effectively creating height. There are also several chimney options that enhance a home’s symmetry, including a single chimney centered above a front door, two flanking the ends of the home, or even four chimneys handsomely anchored to a property’s interior.

At times, a false chimney without venting functionality will be inserted to create balance and symmetry, as shown in the photos below.

In terms of materials, brick and mortar is standard issue. Masons typically choose mortar slightly softer than brick so if structural issues arise, the mortar will deteriorate first. Mortar can be easily re-pointed without the expense of replacing brick, allowing for targeted maintenance and care.

Particularly in New England, alongside traditional red brick, sometimes white painted chimneys with black painted caps are seen. Originating during the American Revolution and termed Tory chimneys, these painted structures were a quiet signal which indicated that a home’s residents were loyal subjects of the British Crown.

Fieldstone is another favorite chimney material. Stone adds beautiful rustic charm and is available in a variety of textures and colors. Fieldstone can be used in its natural state or may be cut and shaped depending on desired aesthetic.

To further stylize the chimney line, many are adorned at the top with caps or pots. Pots are made from materials including terracotta clay, brick, or copper. While pots may be seen as ornamental, they also serve the practical purpose of creating a taller smokestack which increases a chimney’s draw. Fires need oxygen to burn and maximize heat distribution, and a taller smokestack will extend the chimney’s draft. As a final touch, some chimneys are capped to protect the opening from entry by inclement weather or uninvited animals.

If this discussion of chimneys has you rethinking your home’s hearths, contact us to learn how we might approach the project.  In the interim, we invite you to find meaningful inspiration in our portfolio.