Firebrick is mainly used to line surfaces to withstand high temperatures, like the interior walls of kilns, pizza ovens, foundry furnaces, boilers, and fire pits. Made with ceramic fiber material, these insulating firebricks (IFB) also help to improve energy efficiency for the places they are used. Fireproof bricks, also known as refractory cement tiles, are good to use against higher temperatures because of their ability to maintain effectiveness. High duty kiln bricks have a high thermal conductivity, which makes them great for such a purpose.

Mutual Materials clay firebrick is manufactured to comply with the physical properties and characteristics specified by ASTM C 1261, Standard Specification for Firebox Brick for Residential Fireplaces. Heat resistant bricks are specifically designed for use in wood fireplace inserts or stoves and are not meant for exposed outdoor use, veneer wall or horizontal paving applications.

Mutual Materials firebrick is manufactured from a special blend of clay and shale to produce a hard-fired refractory brick capable of resisting the high heat produced in a common fireplace or wood stove. Available in full size and thin size fire clay bricks.

Maximum recommended temperature: 2700 Fahrenheit.

Find medium duty or super duty firebrick and many other best seller masonry products you need for your home improvement projects at Mutual Materials.

Mutual Materials Co. accepts no liability or responsibility for the misuse of products purchased which includes, but is not limited to, improper installation and/or application of product. 

Firebrick is available for online purchase through our Mutual Materials Online Store.


  • Fire Pit

Next Steps

  • Full-Size Firebrick

    • Dimensions: 9" x 4.5" x 2.5"
  • Firebrick Splits

    • Dimensions: 9" x 4.5" x 1.5"

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