A ‘cladding system’ refers to a non-load bearing external layer of a building or its ‘outer skin’, that is applied to high-rise buildings with the purpose of increasing thermal insulation and improving building aesthetics without compromising weather resistance.
The fire risk of a cladding system comes from the fact that in a fire situation, a cladding system that is not fit for purpose has the potential to spread fire rapidly across the external layer of the building, bypassing the buildings internal fire compartmentation and affecting all of the occupied spaces within.
As highlighted in the Grenfell Tower Inquiry Phase 2 report, published in September 2024, it is of paramount importance that your external cladding system is correctly tested to ensure that your system meets the minimum life safety requirements set out in the building regulations. One of the current options is a fire test to BS 8414. This advice and guidance article will outline what a BS 8414 cladding system test is, why a BS 8414 cladding test is important for your building, and how the Fire Protection Association can help.
What happens during a BS 8414 cladding test?
The customer installs their cladding system onto one of our test rigs. They have the option of using either a steel frame or masonry test rig, based on the intended end use.
The cladding system must be 9.7m high and around 4.1m wide depending on the system with a 2m x 2m opening at the bottom for the burn chamber.
Around 400kg of wood is placed into the burn chamber, which produces a heat output around 3MW, intended to represent a room in flashover, with flames venting out a window and attacking the façade.
We let the wooden crib burn for 30 minutes, before extinguishing the crib, and then monitor any burning which continues through the cladding system. The total test last for 60 minutes.
Systems are assessed based on the requirements of BR 135, with most of the assessment based on temperature measurements to determine if fire has spread up the cladding system. There are also considerations for visual observations and mechanical performance.
What does a successful BS 8414 test show?
The BS 8414 standard tells you how to conduct a test and produce results, it does not tell you how to analyse those results. BR 135 is used to assess system performance with only two possible outcomes from a BR 135 assessment:
- System met the requirements of BR 135
- System did not meet the requirements of BR 135
The results of a successful BR 135 assessment can be used to support the use of the cladding system on any building under 18m, in accordance with the guidance in Approved Document B (ADB). They can also be used as part of a fire engineering assessment, by a suitably qualified fire engineer.
If a system does not meet the requirements of BR 135, ADB does not recommend its use on any building over 11m. It would suggest that the system is only appropriate for buildings under 11m, more than 1m from a relevant boundary, and is not used for assembly or recreation purposes.
It should be noted that the Grenfell Tower Inquiry Phase 2 report questioned the performance criteria in BR 135 stating that it could not be clearly linked to the functional requirements in the Building Regulations or the guidance in Approved Document B. It recommends the development of a new test method and updates to the guidance in ADB.
The FPA authored a fire test and assessment method - RISC 501 in 2023, which addresses some of the Inquiry’s concerns and recommendations. More information can be found here.
How can the FPA help?
The Fire Protection Association are accredited by UKAS to carry out BS 8414 cladding testing, and can provide a number of benefits to you in the process including the following:
- Full UKAS accreditation for delivery of BS 8414 cladding testing
- We are currently one of very few companies currently offering BS 8414 cladding testing in the UK
- We carry out material identification analysis on materials subjected to BS 8414 testing to produce a chemical fingerprint of what has been tested and ensure the integrity of our reports
- Cladding testing is completed at our UK-based FPA laboratory in Gloucestershire. Our facility has four full-height testing rigs for conducting testing
- Competitive pricing
- Experienced laboratory staff
- Independent and impartial cladding test results
- Excellent reporting turnaround times
You can find out more about BS 8414 cladding testing at the Fire Protection Association here.
Please be aware that considerable efforts have been made to ensure the accuracy of the information contained within this article at the time of publication, however any legislative (or other) changes that come into effect after this may render the information out of date until it is reviewed and updated as part of the FPA’s content review cycle.