Brick – basic ingredient in clay.
Three Principal Forms:
1. Surface Clay – found near the surface of the earth
2. Shales – clay which have been subjected to high pressure until they have become relatively hard.
3. Fire Clay – found at deeper levels and usually have more uniform physical and chemical qualities.
Two Classes of Clay:
1. Calcareous Clays – contains about 15 percent calcium carbonate and burn to a yellowish color.
2. Non-calcareous Clays – composed of silicate of alumina, with feldspar and iron oxide. These clays burn buff, red or salmon depending on the iron oxide content which vary from 2 to 10 percent.
Standard Brick Size is 2 ¼ x 3 ¾ x 8 inches
Structural Clay Tiles – are hollow units as opposed to brick which is sold. Tiles are made from the same material as brick, but all clay tiles are formed by extrusion in the stiff-mud process.
Types of Tiles:
1. Load bearing wall tile – used for bearing walls of light buildings, the height usually restricted to four stories. Structural load bearing wall tile are made in 4, 6, 8, 10 and 12 in thickness.
2. Partition tile – non-load bearing
3. Back-up tile – intended for use in both bearing and non-bearing walls which will be faced with brick or facing tile.
4. Furring tile – used on the inside of exterior walls to provide air spaces for insulation to prevent the passage of moisture and to provide a suitable plastering surface. Classified as non-load bearing.
5. Fireproofing tile – structural steel must be insulated in fireproof construction. One method of doing this is to cover it with fire-proofing tile.
6. Floor tile – manufactured in both load-bearing and non-load bearing grades in standard thickness raging from 3 to 12 inches in standard length and widths of 12 inches.
7. Structural Clay Facing tile – unglazed tile and may have either a smooth or a rough textured finish. They are designed to used as exposed facing material on either exterior or interior walls and partitions.
8. Structural Glazed Facing tile – produced from high-grade light burning clay which is suitable for the application of ceramic or salt glaze.
Terra Cotta – means “fired earth” is a clay product which has been used for architectural decorative purposes, since ancient Greece and Rome. Modern terracotta is machine-extruded and molded or pressed. The machine-made product is usually referred to as ceramic veneer, and is a unit with flat face and flat or ribbed back.
Two Types of Ceramic Veneer:
1. Adhesion Type – held to the wall by the bond of the mortar to the ceramic veneer back and to the backing wall.
2. Anchor type – are held y mortar and by wire tiles between the terracotta and the wall behind.