BS 8414-2-2020 pdf free download.Fire performance of external cladding systems Part 2: Test method for non‑loadbearing external cladding systems fixed to, and supported by, a structural steel frame.
This part of BS 8414 provides a test method for determining the fire performance characteristics of non‑loadbearing external cladding systems when fixed to, and supported by, a structural steel frame and exposed to an external fire under controlled conditions. The peak fire exposure is intended to be representative of an external fire source or a fully developed (post‑flashover) fire in a room venting from an aperture that exposes the cladding to the effects of external flames.
This part of BS 8414 is solely intended to give an indication of fire spread across or within an external cladding system. The purpose of the test is to provide data to enable evaluation of the fire performance of the components when combined to form a complete cladding system.
This part of BS 8414 does not apply to non‑loadbearing external rainscreen overcladding systems or external wall insulation systems applied to the face of a building, the fire testing of which is covered in BS 8414‑1.
This part of BS 8414 does not cover the performance of glass or its supporting frame intended for glazed window openings.
This part of BS 8414 does not apply to glazed curtain walling systems.
This part of BS 8414 does not test the total configuration of a construction incorporating additional windows, doors, balconies or ancillary penetrations.
This part of BS 8414 does not cover exposure to radiant heat from a fire in an adjacent building.
NOTE 1 Performance criteria and classification methodology for the external fire performance can be found in references such as Report BR 135 [2].
NOTE 2 Further information on the application of results from BS 8414‑2 is given in BS 9414.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes provisions of this document. 1) For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
BS EN 60584‑1:2013, Thermocouples? –? Part? 1:EMF? specifications and tolerances
BS EN ISO 13943, Fire safety – Vocabulary 2)
3 Terms and definitions
For the purposes of this part of BS 8414, the terms and definitions given in BS EN ISO 13943 and the following apply.
3.1 cavity barrier
any construction provided to seal a cavity against the penetration of fire and smoke or to restrict its movement within the cavity
3.2 collapse
any part of the cladding system which falls away and becomes detached
3.3 damaged area
total of those surface areas which have been affected permanently by fire under specified conditions
[SOURCE: BS EN ISO 13943:2017, 3.72]
NOTE 1 Area is expressed as a percentage.
NOTE? 2? Users? of? this? term? should? specify? the? types? of? damage? to? be? considered.? This? could? include? loss? of? material,?
deformation,? softening,? melting,? charring,? combustion,? pyrolysis? or? chemical? attack.
3.4 external cladding system
complete cladding assembly
3.5 firebreak
non‑loadbearing vertically or horizontally oriented element designed to restrict fire spread within one or more layers of an external cladding system
3.6 level 1
2 500 mm above the top of the combustion chamber opening in the test apparatus 3.7 level 2
5 000 mm above the top of the combustion chamber opening in the test apparatus 3.8 level 3
7 500 mm above the top of the combustion chamber opening in the test apparatus 3.9 start temperature, T s
mean temperature of the thermocouples at level 1 during the 5 min prior to ignition of the heat source
3.10 start time, t s
time when the temperature recorded by any external thermocouple at level 1 equals or exceeds a 200 °C temperature rise above T s and remains above this value for at least 30 s.
4 Principle In this test, the external cladding system is fixed to, and supported by, a structural steel frame in the form of a main face together with a perpendicular side wing, with the cladding system attached in the manner specified by the test sponsor. At the base of the vertical system, an opening is provided through which the fire can vent.BS 8414-2 pdf download.