FireRock Adhesive Mortar is a specially formulated mortar - a low sand polymer modified with heat resistant additives - and is designed to work as a “glue” rather than a typical joint provider. This mortar must be used to install the firebox in order for the FireRock warranty to be valid. It may also be used to install the firebrick, though substitutions are allowed. Substitutions in the firebox will result in a non-compliant unit and will invalidate the FireRock warranty.
