Bricks of a typically rectangular shape are cast from a mixture of clay, sand and small amounts of admixture and fired in a kiln at temperatures between 700 and 1100 ∞C (1300 and 2000 ∞F). This heating takes the clay through several stages, including the burn-off of carbon and sulfur, driving off chemically combined water from the clay, quartz inversion, sintering and vitrification. At the end of this firing process, the clay brick is hard and will not soften when it reacts with water.

Bricks are laid in successive courses, bonded by a mortar of clay/sand, lime/sand or lime/cement/sand. There are many different patterns for brickwork, but most feature offset joints between courses. Keystone arches can be formed to create self-supporting openings, or metal reinforcement is used to form straight openings.

When used as cladding, bricks are attached to the structural sheathing by means of metal ties that are nailed to the wall and embedded in the mortar joint, and a space is left between the brick and the sheathing to create a rainscreen. Weeper holes are left at intervals in the top and bottom courses to allow moisture to escape.

When used structurally, brick walls are typically one part of a double masonry wall, with an insulated core between the two wythes. Ties are placed at intervals between the two walls to increase stability. Structural brick walls are also built using a doublewide arrangement of bricks. It is rare for fired clay bricks to be used structurally in modern construction in North America.

While both refractory bricks and fire bricks are designed for high-temperature applications, there are some critical differences that make them suitable for different purposes:

1. Composition: Refractory bricks, including SiC refractory bricks, are typically made from materials like silicon carbide, alumina, zirconia or are containing a higher amount of mullite. Fire bricks, on the other hand, are primarily composed of clay minerals and alumina or mullite in lower quantities
2. Thermal properties: Refractory bricks generally have a higher thermal conductivity as of their higher density
3. Application-specific performance: Refractory bricks are designed for specific high-temperature applications and environments, offering better performance in terms of wear, corrosion because of direct contact with the corrosive media, and thermal resistance. Fire bricks, while suitable for general high-temperature applications, may not perform as well in more demanding environments and have a limited maximum temperature of use.
4. Cost: Due to their high quality raw materials and properties, cost of refractory bricks is typically premium compared to fire bricks.