NBN EN 845-2:2013

This European Standard specifies requirements for prefabricated lintels for maximum spans of 4,5 m and made from steel, autoclaved aerated concrete, manufactured stone, concrete, fired clay units, calcium silicate units, natural stone units, or a combination of these materials. Concrete and steel beams conforming to EN 1090-1, EN 12602 and EN 13225, as appropriate, are not covered by this standard.
Prefabricated lintels can be either complete lintels or the prefabricated part of a composite lintel.
This European Standard is not applicable to:
a) lintels completely made on site;
b) lintels of which the tensile parts are made on site;
c) timber lintels;
d) natural stone lintels, not reinforced.
Linear components spanning clear openings greater than 4,5 m in masonry walls and linear components intended for use independently in a structural role (e.g. beams) are not covered by this standard.