This heading covers non-refractory ceramic bricks (i.e., bricks unable to withstand temperatures of 1,500 ¡ÆC or higher) of the kinds commonly used for building walls, houses, industrial chimney-stacks, etc. Such bricks remain in the heading even if they can also be used for other purposes (e.g., vitrified bricks which can be used for paving or bridge piling, as well as for the construction of buildings).
Bricks are usually relatively porous (common pottery), but some are more or less vitrified (stoneware or engineering bricks) and are then used in constructional work calling for great mechanical strength or resistance to acids (e.g., in chemical plant). The heading includes :(1) Ordinary solid bricks of rectangular shape, with flat or indented surfaces. (2) Curved bricks, sometimes perforated, for industrial chimney-stacks. (3) Hollow bricks, perforated bricks; long hollow flooring blocks and constructional slabs used particularly for flooring, ceilings, etc., in combination with structural steelwork, and support or filler tiles (i.e., ceramic fittings designed to support the blocks while encasing the girders). (4) Facing bricks (e.g., for facing houses or walls, the surrounds of doors or windows, including special bricks for column capitals, borders, friezes or other architectural decoration). So-called "double" bricks specially perforated lengthwise, ready for splitting before use, remain in this heading provided that they retain the character of building bricks after separation. All these bricks, especially those intended for facing, may be polished, sand-faced (by fusing sand on to the surface during firing), covered with a thin layer of white or coloured slip which hides the colour of the body, smoked or flamed, coloured in the body or on the surface (by adding metallic oxides, by using ferruginous clay, or by heating in a reducing atmosphere with hydrocarbons or carbon), impregnated with tar, or glazed, etc. They may also have moulded, embossed or indented designs on one or two faces. The heading also includes light bricks made from mixtures containing sawdust, peat fibres, chopped straw, etc., which are burned away during firing, leaving a very porous structure. The heading does not cover : (a) Bricks of kieselguhr, etc. (heading 69.01) and refractory bricks (heading 69.02). (b) Flags and paving, hearth or wall tiles (see Explanatory Notes to headings 69.07 and 69.08).
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