BS EN 492:2012 pdf download – Fibre-cement slates and fittings — Product specification and test methods 5.1.2 Appearance and finish The exposed face of the fibre-cement slates may be with or without texture. The fibre-cement slates may be coloured or left in their natural colour. The fibre-cement slates may also receive adherent coloured or uncoloured coatings on their surface. The fibre-cement slates may be supplied with holes for fixing. On exposure, the surface and/or its coating will be affected by weathering which may vary with site location, aspect, pitch of roof and duration of exposure. Any deterioration in this respect shall not detract from the minimum mechanical and physical characteristics as specified in this document or from the function of the fibre-cement slate as a durable element. The fittings shall have a general appearance and finish compatible with the fibre-cement slates with which they are to be used. They may be supplied with holes for fixing. 5.2 Dimensions and tolerance 5.2.1 General The manufacturer shall specify the shapes, sizes and configuration of edges. NOTE See 5.6 for designation and information. Fittings shall have nominal dimensions and shapes determined by the manufacturer and appropriate to the corresponding fibre-cement slates. 5.2.2 Thicknesses The actual fibre-cement slate thickness determined in accordance with 7.2 shall be not less than that shown in Table 1. The nominal thickness shall be specified by the manufacturer. The nominal thickness of the fittings shall be not less than the corresponding nominal thickness of the fibrecement slates with which the fittings are to be used. 5.2.3 Tolerances on nominal dimensions The maximum dimensional variation when measured as specified in 7.2 shall be as follows: Length and width: ± 3 mm; Thickness: 25 10 + − % of the nominal value. For fittings that replace fibre-cement slates (e.g. ventilation fibre-cement slates) the tolerances shall be the same as those on the fibre-cement slates. For other fittings (e.g. ridges) the tolerances shall be specified by the manufacturer. 5.3 Physical requirements and characteristics for fibre-cement slates 5.3.1 General Mechanical and material properties are determined on products as delivered, wherever practicable. The results shall be identified as applying to coated or uncoated material. NOTE See 6.3 for statistical interpretation. 5.3.2 Apparent density The manufacturer’s literature shall specify the minimum apparent density of the fibre-cement slates. The fibrecement slates shall have an apparent density equal to or greater than that specified by the...
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