Masonry Magazine June 1979 Page. 16
solid brick. hollow brick, structural facing tile
(glazed or unglazed) and structural clay tile.
ASTM standards are under continuous review by the standing committees having jurisdiction over them. From time to time these standards are revised as a result of new developments. The ASTM designation of a standard consists of a letter and a number permanently assigned to the standard, a dash and a number indicating the year the standard was approved: as for example. C 216-69 which designates the Standard Specifications for Facing Brick approved in 1969. If the letter T follows the year designation, it indicates a tentative standard.
When ASTM specifications are included by reference in project specifications, the full designation, including the year of approval, should be given, since, obviously, after a contract has been awarded, a revision of specifications by ASTM does not alter the contract. Similarly, the dates of any other specifications or codes included by reference should be given.
Solid Masonry Units
Solid Masonry Units. ASTM Specifications C 216. C 62, and C 126 cover solid building brick. facing brick and ceramic glazed units made from clay and/or shale. Under these specifications, a solid masonry unit may be cored not in excess of 25 per cent; consequently, the term "solid brick" is not confined to those units which have no cores, unless so stated in the project specifications.
Hollow Masonry Units
Hollow Masonry Units. ASTM Specification C 652 covers hollow building brick, facing brick or hollow masonry units made from clay, shale, fire clay or mixtures thereof, and fired. The term "hollow" in this specification is defined to mean any unit cored in excess of 25 per cent, but not more than 40 per cent, in every plane parallel to the bearing surface.
Supplementary Requirements
Supplementary Requirements. ASTM specifications for brick and tile do not fix the size or color and texture of the units. They do, however, include requirements for several grades and types of products, and some of them contain optional requirements which are applicable to specific projects, if so specified.
When ASTM specifications are included in project specifications by reference, it is essential that they be supplemented with project requirements covering size, color, grade, type, etc. Without these supplementary provisions, the specifications are incomplete and inadequate as a basis for estimating.
Size
Size. Size of units required should be included in the project specifications. Without this information, a contractor cannot accurately estimate quantity of materials or the labor required to construct the masonry.
It is recommended that the specified size be the manufactured size. Individual unit dimensions may vary from the specified or manufactured size by the allowable tolerances included in the appropriate ASTM specifications for the particular type or grade.
Specifying nominal sizes of clay masonry units is not recommended, due to the ambiguity of the term "nominal". In some fields, it is understood to mean approximate and actual dimensions may vary from the nominal only by permissible variations in dimensions included in the specifications. However, in modular design, the nominal dimension of a masonry unit is understood to mean the specified or manufactured dimension plus the thickness of the mortar joint with which the unit is designed to be laid; that is, modular brick, whose nominal length is 8 in., would have a specified (manufactured) length of 7 1/2 in. if designed to be laid with a 1/2-in. joint, or 7 5/8 in. if designed to be laid with a 3/8-in joint.
Color and Texture
Color and Texture. Generally, the color and texture of the brick or structural facing tile in a masonry wall vary slightly. These variations, which prevent monotony in the appearance of the finished wall, are one of the most attractive features of brick and tile. Because of these variations and of the wide variety of colors and textures produced by the industry, it is impossible to write descriptions of either color or texture which will accurately identify the products required.
For this reason, ASTM specifications for brick and structural clay facing tile provide that texture and color shall conform to an approved sample showing the full range of color and texture that will be acceptable. The number of units required in the sample should be stated in the project specifications and will depend upon the range of color and texture. In general, it will be from three to five,
Grade and Type
Grade and Type. Most ASTM specifications for brick or structural clay tile cover two or more grades, and specifications for facing brick, hollow brick and ceramic glazed structural facing tile include requirements for two or more types. Specifications for structural clay facing tile cover two types and two classes.
When these specifications are included in project specifications by reference, it is essential that the grade and type or type and class of product required be specified. Failure to do so makes it difficult for the contractor to estimate the project and frequently results in a demand for extras after the contract is awarded.
Cell Arrangement
Cell Arrangement. Structural clay tile are produced with either vertical cells or horizontal