Cast Stone Chimney Extensions

Residential Cast Stone
Cast Stone Institute 2016 MANUFACTURING EXCELLENCE Award Winner
Cast Stone Institute 2017 UNIQUE ARCHITECTURAL FEATURE EXCELLENCE Award Winner

This unique application of cast stone called for the fabrication of five custom decorative chimney extensions. Incorporating five unique designs and shapes, the pieces fit over the original chimneys of a large private estate.

The role of cast stone was to create stunning visual appeal by the incorporation of highly decorative chimney extension. The design intended to replicate old world architecture.

The chimney designs created significant mold fabrication and casting challenges. Each chimney had unique dimensions and radii, each with different architectural artwork on the exterior. The “through the wall” decorative patterns near the tops of the chimneys ultimately serve as the outlet for the chimneys, while creating their striking architectural appearance. Incorporating all of the various architectural details into the relatively small mold space proved to be a significant challenge.

The molding process was extremely complex, as each chimney had unique designs, and different radii, requiring a new mold for each chimney. The recessed architectural features required hundreds of individual elements to be handmade and custom shaped to fit the radius of the mold surface.

The largest challenge of the project was incorporating the unique architectural elements while meeting the overall functionality requirements of a chimney extension. Additionally, these cast stone chimneys also have a solid one-piece cap, which prevents rain and snow from entering directly into the chimney flue.

100+ years ago, these types of elements would have been handcrafted onsite, many times out of individual bricks. The custom cast stone elements replicated this old-world architecture beautifully. They also allowed the units to be installed very quickly onsite. The chimneys create not only stunning visual interest, but also serve the utility function of chimney extensions.


“Complexity is impressive and each one is different”

“Difficulty in design, production and installation”

“True to the style and supports the architect. Beautiful!”

“The chimney tops were so unique they made the mansion.”

“The mold work was a manufacturing marvel. Such a difficult project done very well.”

CSI Award Judges Comments