BS 8414-2:2020 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

BS 8414-2:2020 pdf free.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.
5.2 Structural steel test frame
The structural steel test frame shall be designed and constructed to withstand the expected loading imposed by the system under test and any subsequent distortions that can occur during the test programme. All details shall be recorded.
NOTE Annex B shows a typical structural steel test frame (see Figure B.1). The test specimen installation might need modification of or additions to, an existing base test frame.
5.3 Main test apparatus wall (main face)
The main test apparatus wall onto which the test specimen is applied shall be:
a) vertical, extending (7 700 ±100) mm above the top of the combustion chamber opening; and b) at least 2 600 mm wide.
5.4 Return wall (wing)
The return test apparatus (wing) wail onto which the test specimen is applied shall be:
a) vertical, of the same height as the main test wall;
h) at least 1 500 mm wide; and
c) perpendicular to the main test apparatus wall.
5.5 Combustion chamber
The combustion chamber shall be constructed in accordance with the dimensions shown in Figure 1. including the provision of a robust lintel across the head of the chamber opening and a solid platform able to support the heat source. The combustion chamber shall be capable of enduring the effects of the test procedure without itself suffering undue damage or distortion.
NOTE A nominal cross-section of 200 mm x 200 mm produced from C25/30 grade concrete has been found to produce a suitable lintel.
The combustion chamber shall be positioned at the base of the vertical main test apparatus wall and fully sealed to prevent air ingress, except for an opening such that the fire can project through the opening at the base of the vertical main test apparatus wall.
The top of the chamber opening shall be (2 000 ±100) mm above the base of the test facility and shall be (2 000 ± 100) mm wide.
A distance of (260 ± 100) mm shall be allowed from the side of the opening of the combustion chamber to the finished face of the test specimen under test (see Figure 1). A timber crib heat source (5) shall be installed within the combustion chamber.
5.6 Timber crib heat source
The timber crib heat source shall be as specified in Annex A.
5.7 Thermocouples
5.7.1 General
All thermocouples shall conform to BS EN 60584-1:2013, Type K (Chromel/Alumel). The thermocouples shall be mineral insulated and have a 1.5 mm (nominal) diameter with insulated junctions. At each specified level, temperatures shall be monitored using thermocouples positioned in accordance with 5.7.2 and 5.7.3.
5.7.2 External thermocouples
5.7.2.1 General
External thermocouples shall be positioned to a tolerance of ±10 mm with the hot junction positioned (50 ±5) mm in front of the face of the test specimen.
5.7.2.2 External thermocouples at levels 1, 2 and 3
External thermocouples shall be located at levels 1, 2 and 3 on the test specimen as follows (see Figure 2).
a) Thermocouples shall be positioned in front of the main test wall face on the centre line and at 500 mm and 1 000 mm each side of the centre line of the combustion chamber (five locations).
b) Thermocouples shall be positioned in front of the wing test wall face, at 150 mm, 600 mm and 1 050 mm from the finished face of the main test wall face (three locations).
NOTE Levels 1, 2 and 3 are meant to represent floor spacing in a building. The results obtained from levels at the distances above the combustion chamber opening stipulated in Figure 2 are valid for greater floor separation distances.
5.7.3 Internal thermocouples
5.7.3.1 General
Internal thermocouples shall be positioned at level 2 and level 3 only to a tolerance of±10 mm in accordance with 5.7.3.2 and Figure 2 and clear of any cavity barrier.
NOTE For cases where the cavity barrier coincides with thermocouples at level 3 (ie. 7500 mm above the top of the combustion chamber), the edge of the slab should be moved downwards to allow the cavity barrier to be fixed at least 50 mm below the thermocouples.
They shall be positioned at the mid-point of each layer and cavity with a depth 10 mm.
5.7.3.2 Internal thermocouples location
Internal thermocouples at level 2 and level 3 of the test specimen shall be located as follows (see Figure 2).
a) Thermocouples shall be positioned within each layer of the main test wall face on the centre line and at 500 mm and 1 000 mm each side of the centre line of the combustion chamber (five locations).
b) Thermocouples shall be positioned within each layer of the wing test wall face, at 150 mm, 600 mm and 1 050 mm from the finished face of the main test wall face (three locations).
5.8 Early test termination reference line
A reference line shall be drawn horizontally across the main face and wing at level 3 to aid in observation of the vertical flame spread for the purposes of early test termination criteria (see 8.6).
5.9 Data acquisition system
A data acquisition system capable of recording data at 10 s intervals shall be connected to the instruments.
5.10 Audio-visual equipment
A continuous audio-visual record of the full height of both external test faces shall be taken throughout the period of the test. The recording shall capture the full duration of the test and record full details of fire spread and mechanical performance in such detail that a full evaluation of the system performance is possible. The quality of the recording shall be such that it enables the extraction of clear still images.
Both the external and innermost faces of the test specimen shall be monitored.
5.11 Environmental test condition monitoring equipment
Equipment for monitoring wind speed, such as an anemometer, shall have an accuracy of ±U.1 m/s for measuring the ambient air velocity.
5.12 Timing device
The timing device used, such as a clock, shall have an accuracy of greater than 5 s/h.
6 Test specimen
6.1 General
A test specimen shall be obtained from the test sponsor which:
a) is representative of the intended end use design and consists of all relevant components of the intended specification;
b) references the associated component manufacturer’s design specification and installation details; and
c) is assembled and installed in accordance with the test sponsor’s instructions, as would be expected in practice.
NOTE 1 All components provided by the test sponsor are considered part of the test specimen.
NOTE 2 It is the responsibility of the test sponsor to Inform the test laboratory of any variations to the manufacturer’s design specification and installation details. It is expected that any deviation from a manufacturer’s design specification and installation details would be highlighted by the test sponsor and recorded in the test report.
6.2 Dimensions and details of the test specimen
NOTE 1 The maximum thickness of the system is effectively limited only by the relevant steel test frame design (see Annex B).
The test specimen shall extend horizontally from the finished internal corner between the main face and the wing for a distance of at least 2 400 mm on the main face and a distance of at least 1 200 mm on the wing. The test specimen shall extend from the base of the test apparatus to a height of(7 700±100) mm above the top of the combustion chamber opening on both the main face and the wing. The test specimen shall not obstruct the combustion chamber opening.
The perimeter of the cladding system around the combustion chamber shall incorporate products, details and components that are as intended for the closure of the aperture and associated cavities in the end use design.
NOTE 2 Examples of components include membranes, window frames (including batons, fixings, polyurethane (builder’s) foam] and cavity barriers/fl re breaks.
If the external cladding system is not intended to offer any protection to openings in practice, the interface between the test specimen and the combustion chamber shall remain unprotected.
Edge detailing and terminations shall be as intended for the end use design, and shall be recorded.BS 8414-2 pdf download.BS 8414-2:2020 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