Soapstone Fireboxes

The Rumford Store
Firebrick Guarantee
7/29/10

All the brick and stone that we sell for building a firebox will withstand the heat of a fireplace - up to about 2,000 degrees F - under normal use. "Normal use" means not burning trash or Christmas trees and not dowsing the fire with water or hitting it with a sledge hammar.

Not all the brick or stone we sell for building fireboxes has been tested or meets ASTM C27 or C1261 which are the firebrick standards that code references. But firebrick is not required by code. Code just allows the firebox walls to be 8" thick instead of 10" thick if you do use firebrick. Here is the language:

R1001.5 Firebox walls. Masonry fireboxes shall be constructed of solid masonry units, hollow masonry units grouted solid, stone or concrete. When a lining of firebrick at least 2 inches (51 mm) thick or other approved lining is provided, the minimum thickness of back and side walls shall each be 8 inches (203 mm) of solid masonry, including the lining. The width of joints between firebricks shall not be greater than 1/4 inch (6 mm). When no lining is provided, the total minimum thickness of back and sidewalls shall be 10 inches (254 mm) of solid masonry. Firebrick shall conform to ASTM C 27 or C 1261 and shall be laid with medium duty refractory mortar conforming to ASTM C 199.

The important thing is that whatever brick or stone you use in the firebox not crack or spall from the heat of the fire under normal use. If it does, our providers have agreed to replace the brick or stone - not instal it or rebuild your fireplace - just replace the brick or stone that failed.