Substitute for firebricks can be old red clay solid bricks. In ovens these alternative red clay bricks will heat up, retain heat, cook, bake, roast, re-fire, absorb conduct store and hold the heat from wood fire and perform the same way as proper refractory firebricks do.

Are clay bricks fire resistant?

Fire bricks is different from that of red bricks in the chemical composition, color, shape and properties. Fire bricks are made of clay containing alumina and silica. … Medium-grade fire brick is the most heat resistant and ideal for a brick oven, reaching top temperatures of around 900 degrees F.

How can you tell if a brick is fireproof?

Firebricks are commonly whitish or pale yellow, though there may be other colors. They will be very exact in dimensions and edges, though used ones may have chips and ragged edges. You don’t want any bricks that have a series of holes through them; that is an indication (not the only one) of newer hard common bricks.