Chimney blocks are one-piece interlocking components that make it easy to add an all-masonry chimney to your indoor or outdoor fireplace. These nesting chimney blocks can be stacked as high as building code allows, and have been independently tested at a compressive strength of 3,000 PSI. To further increase the strength of our chimneys, rebar and mortar can be placed into the “hurricane” holes.

Use with FireRock’s brick flange to add brick, stone, or stucco veneer above the roofline. One (1) bag of FireRock mortar is needed for every 6 masonry chimney blocks.

Note: Please consult local building codes for specifics regarding any masonry fireplace application.

Specifications