Flooring tiles Flooring tiles include small and medium-sized units in thicknesses of 5 mm to 35 mm, larger thicker units, or bricks used for paving. As sizes and shapes of these products are extremely varied, please refer to manufacturers' catalogues for additional information. The laying of floor tiles must conform to the specifications set forth in French standard NF P 61-202-1 "Sealed flooring". Ceramic tiles may also be set with certain mortar adhesives. Whenever possible, Technical Assessments issued by the CSTB (Centre Scientifique et Technique du Bâtiment) should be consulted, as should the specifications detailed in the French-language technical recommendations entitled "Revêtement de sols intérieurs et extérieurs en carreaux céramiques collés au moyen de mortiers colles"; manufacturers' instructions should also be followed strictly. Paving bricks Clay pavers are solid or perforated masonry units, generally square or rectangular in shape and with or without bevelling. They may come in other shapes designed to enhance beauty or improve fixation. Pavers are less than 300 mm in length, in thicknesses greater than 40 mm. Their characteristics must conform to French standard NF P 98-336 "Clay pavers for external surfaces". They can be laid on sand or mortar, in conformity with French standard NF P 98-335 "Laying of concrete pavement setts and slabs, paving bricks, and pavement setts and slabs of natural stone".