Brick is the oldest manufactured building material. The earliest brick, made from mud (sometimes with added straw), was invented almost 10,000 years ago. Clay brick started to appear about 5000 years ago, when builders borrowed pottery manufacturing techniques to improve its strength and durability. From some of the oldest known structures to modern buildings, clay brick has a history of providing shelter that is durable, comfortable, safe, and attractive.

Primary raw materials for modern clay bricks include surface clays, fire clays, shales or combinations of these. Units are formed by extrusion, molding or dry-pressing and are fired in a kiln at high temperatures to produce units with a wide range of colors, textures, sizes and physical properties. Clay and shale masonry units are most frequently selected as a construction material for their aesthetics and long-term performance.

While brick and structural clay tile are both visually appealing and durable, they are also well-suited for many structural applications. This is primarily due to their variety of sizes and very high compressive strength.

For more information, contact the Brick Industry Association

Architect Magazine Profiles Brick Plant

The May 2008 issue of Architect magazine from Hanley-Wood takes a look at how clay brick are manufactured. Authors note that brick are “beautiful, …plastic, …and last practically forever.” Like block, brick are often manufactured and used locally, which along with their durability, makes them a sustainable building material.

Although brick’s history dates back to at least 7000 B.C., today’s manufacturing methods are very similar to those used starting around 3000 B.C., when firing became a popular manufacturing method. Made from a basic recipe of shale, clay, and water, t today’s brick differ from their predecessors primarily in terms of the speed and efficiency of firing.

The focus of this article is the Belden Brick, Co. in Canton, Ohio. This fifth generation company is still family run, continuing the tradition started in 1885. In the U.S., most brick are manufactured to conform to ASTM C216, Standard Specification for Facing Brick (Solid Masonry Units Made from Clay or Shale). A counterpart, ASTM C62, Standard Specification for Building Brick (Solid Masonry Units Made fom Clay or Shale), covers brick for which external appearance is not a requirement. These standards ensure consistent properties like appearance, durability, absorption (and initial rate of absorption), freezing and thawing resistance, and strength.

Brick are made by mining materials, crushing-grinding-sifting-mixing, molding (by machine, hand, or extrusion), and firing. In recent years, North America brick production has been as high as about 9 billion units annually. A large amount of that material goes to residential construction.

Additional information about brick can be found at The Brick Industry Association Web site.

Various brick manufacturing processes are shown here: extruding a brick column, brick stacks ready for firing, firing brick in kilns.

Extruding a brick column	Brick stacks ready for firing	Firing brick in kilns

 
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