The performance criteria for the BS8414 test is to determine fire spread away from the initial fire source and the rate of fire spread.
As stated in the BRE document Fire Performance of External Thermal Insulation for Walls of Multi-Storey Buildings (third edition), “…If fire spread away from the initial source occurs, the rate of progress of fire spread or tendency for collapse should not unduly hinder intervention by the emergency services”.
The performance of the system was therefore investigated and evaluated against the following three criteria:
External fire spread
Internal fire spread
This means that Gebrik meets Building Regulation B4, which requires the external walls of a building >18m to adequately resist the spread of fire where (in any building) the cladding system and materials must conform or exceed the regulation definition for limited combustibility (or better) or alternatively the wall construction must meet the provisions of BR135.
Likewise external wall cladding less than 1m from a relevant boundary should conform to the same requirement.