NBN EN 1857+A1:2008

This European Standard specifies the material, dimensional and performance requirements, including methods of test, for factory-made concrete flue liners and fittings for the construction of multi-wall chimneys. This standard also relates to storey-height and reinforced flue liners.
NOTE 1: Classes in this standard, unless otherwise specified, e.g. resistance to fire, are not derived from conditions referred to in article 3.2 of Directive 89/106/EC, and should only be considered as technical classes in the sense of Commission Guidance Paper E 'Levels and classes in the Construction Products Directive'.
NOTE 2 : Any reference to the term flue liners implies both flue liners and their fittings, except where otherwise indicated.
The amendment introduces resistance to freeze/thaw as essential characteristic.