Brick have been made in a wide range of sizes and shapes, from the old Greek brick, which was practically a 23-in cube of 12,650 in3 volume, to the small Belgian brick, about 13â„4 x 33â„8 x 41â„2 in with a total volume of only 27 in3. The present common nominal sizes in the United States are 4 or 6 in thick by 22â„3 or 4 in high by 8 or 12 in long. For a list of modular sizes, see Standard Sizes of Clay and Concrete Modular Masonry Units, ANSI A62.3. Actual dimensions are smaller, usually by the amount of the width of the mortar joint. Current specification requirements for strength and absorption of building brick are given in Table 4.8 (see ASTM C652, C62, and C216). Strength and absorption of brick from different producers vary widely.
Thermal expansion of brick may range from 0.0000017 per F for fire-clay brick to 0.0000069 per F for surface-clay brick. Wetting tests of brick indicated expansions varying from 0.0005 to 0.025%.
The thermal conductivity of dry brick as measured by several investigators ranges from 1.29 to 3.79 Btu/ (hr)(ft3)(F)(in). The values are increased by wetting.