BRICK MASONRY

LEARNING OBJECTIVE: Upon completing this section, you should be able to explain the elements of brick masonry.

Brick masonry is construction in which uniform units ("bricks"), small enough to be placed with one hand, are laid in courses with mortar joints to form walls. Bricks are kiln baked from various clay and shale mixtures. The chemical and physical characteristics of the ingredients vary considerably. These characteristics and the kiln temperatures combine to produce brick in a variety of colors and harnesses. In some regions, individual pits yield clay or shale which, when ground and moistened, can be formed and baked into durable brick. In other regions, clay or shale from several pits must be mixed.

BRICK TERMINOLOGY

Standard U.S. bricks are 2 1/4-by-3 3/4-by-8 inches nominal size. They may have three core holes or ten core holes. Modular U.S. bricks are 2 1/4-by-3 5/8-by-7 5/8 inches nominal size. They usually have three core holes. English bricks are 3-by-4 1/2-by-9 inches; Roman bricks are 1 1/2-by-4-by-12 inches; and Norman bricks are 2 3/4-by-4-by-12 inches nominal size. Actual brick dimensions are smaller, usually by an amount equal to a mortar joint width. Bricks weigh from 100 to 150 pounds per cubic foot, depending on the ingredients and duration of firing. Fired brick is heavier than under-burned brick. The six surfaces of a brick are called cull, beds, side, end, and face, as shown in figure 8-30.

Occasionally you will have to cut brick into various shapes to fill in spaces at corners and other locations where a full brick does not fit. Figure 8-31 shows the more common cut shapes: half or bat, three-quarter closure, quarter closure, king closure, queen closure, and split.

TYPES OF BRICKS

Brick masonry units may be solid, hollow, or architectural terra cotta. All types can serve a struc- tural function, a decorative function, or a combination of both. The various types differ in their formation and composition.

Building brick, also called common, hard, or kiln-run brick, is made from ordinary clay or shale and is fired in kilns. These bricks have no special shoring, markings, surface texture, or color. Because building bricks are generally used as the backing courses in either solid or cavity brick walls, the harder and more durable types are preferred.

Face brick is better quality and has better durability and appearance than building brick. Because of this, face bricks are used in exposed wall faces. The most common face brick colors are various shades of brown, red, gray, yellow, and white.

Clinker brick is over burned in the kiln. Clinker bricks are usually rough, hard, durable, and sometimes irregular in shape.

Pressed brick is made by a dry-press process rather than by kiln firing. Pressed bricks have regular smooth faces, sharp edges, and perfectly square corners. Ordinarily, they are used like face brick.

Glazed brick has one surface coated with a white or colored ceramic glazing. The glazing forms when mineral ingredients fuse together in a glass like coating during burning. Glazed bricks are particularly

Common cut brick shapes

Figure 8-31.-Common cut brick shapes.