Fibre Reinforced Facade Encyclopedia: Testing and standards
BR 135 is a BRE report, Fire performance of external thermal insulation for walls of multistorey buildings, whose annex sets out the performance criteria against which a BS 8414 full-scale facade fire test is judged. BS 8414 is the test method and it produces data; BR 135 is the yardstick that turns that data into a pass or a fail. A facade system is therefore described as having met the BR 135 criteria when tested to BS 8414.
The two documents are always quoted together and are often confused. BS 8414 describes how to build the rig, light the fire and place the thermocouples. BR 135 says what the readings from those thermocouples are allowed to do.
At a glance
| Property | Typical value | Note |
|---|---|---|
| Publisher | BRE, Building Research Establishment | Third edition published 2013 |
| Full title | Fire performance of external thermal insulation for walls of multistorey buildings | |
| Role | Classification criteria applied to a BS 8414-1 or BS 8414-2 test | BS 8414 itself sets no pass or fail |
| Start of test | When a level 1 external thermocouple exceeds 200 °C above ambient | All timing is measured from this point |
| Level 1 | 2.5 m above the top of the combustion chamber opening | Reference level |
| Level 2 | 5 m above the top of the combustion chamber opening | Failure level |
| External fire spread criterion | Temperature rise above 600 °C sustained for 30 seconds at level 2, within 15 minutes of start | Failure if reached |
| Internal fire spread criterion | The same limit applied to level 2 thermocouples within the cavity | |
| Mechanical performance | Collapse, spalling, delamination and falling debris recorded and assessed | |
| Jurisdiction | United Kingdom; Approved Document B | Not an Australian compliance pathway |
What the criteria actually are
A BS 8414 rig burns a timber crib of defined mass in a combustion chamber at the base of a nine metre high wall, and thermocouples are installed at two horizontal levels above the chamber opening: level 1 at 2.5 metres and level 2 at 5 metres, both on the external surface and within any cavity. BR 135 defines the start of test as the moment any external level 1 thermocouple first exceeds 200 °C above the ambient starting temperature, which anchors all subsequent timing to the point at which the fire has genuinely engaged the facade rather than to ignition of the crib.
External fire spread failure occurs if any external level 2 thermocouple records a temperature rise of more than 600 °C above ambient, sustained for at least 30 seconds, at any time within 15 minutes of the start of test. Internal fire spread failure applies the same limit to level 2 thermocouples inside the cavity and within the insulation layers. Both the sustained duration and the 15 minute window matter: a brief spike does not fail the system, and a failure after the window is outside the classification.
Alongside the temperature criteria, BR 135 requires an assessment of mechanical performance. Collapse of the system, large scale spalling or delamination, and burning debris falling from the rig are recorded by observers and photographed, and they bear on whether the system is judged to have performed acceptably even where the thermocouples stayed within limits.
How a result is expressed
The correct form of words is that the system, in the specific build-up tested, met the performance criteria of BR 135 when tested in accordance with BS 8414 Part 1 or Part 2. Part 1 is for a system applied to a masonry face; Part 2 is for a system applied to a structural steel frame. The two are not interchangeable and the report states which was used.
A BS 8414 result is a system result, not a product result. It covers that combination of panel, insulation, cavity dimension, cavity barriers, brackets, rails, fixings and joints. Change the insulation, widen the cavity or delete a cavity barrier and the test no longer applies. This is the single most important limitation to carry into a submission review, because suppliers commonly present a test of one build-up as evidence for a family of build-ups.
BR 135 and AS 5113
Australia adopted the BS 8414 rig geometry and fire source when it published AS 5113, but wrote its own criteria rather than referencing BR 135. AS 5113 adds requirements that BR 135 does not contain, including limits on flaming debris reaching the ground and on the behaviour of the specimen at defined distances, and it classifies a system as EW or not. A test rig can be instrumented to report against both sets of criteria in one burn, which is how systems are commonly qualified for both markets.
The practical consequence for an Australian project is that a BR 135 statement alone does not demonstrate compliance. What is needed is an AS 5113 classification, or a fire safety engineer’s performance solution that uses the full-scale test data as evidence. Similarly, a North American project needs NFPA 285 and a Canadian project needs CAN/ULC-S134.
ShapeShell-RT and the full-scale test
ShapeShell-RT, the ShapeShift fibre reinforced polymer facade system, passed the full-scale BS 8414 and AS 5113 facade test at BRE Global, meeting all AS 5113 criteria. That test result is the basis of its use on buildings where a non-combustible cladding would otherwise be required, and it is assessed project by project by a fire safety engineer against the tested build-up. ShapeShell-RT is a polymer composite and is not non-combustible; where non-combustibility is the requirement, the relevant ShapeShift product is ShapeShell-RC, which holds an AS/NZS 1530.1 result of Not Deemed Combustible from Ignis Labs.
Standards and references
- BR 135 Fire performance of external thermal insulation for walls of multistorey buildings, third edition, BRE
- BS 8414-1 and BS 8414-2 Fire performance of external cladding systems
- Approved Document B (Fire safety), England; Regulation 7(2) of the Building Regulations 2010
- AS 5113 Classification of external walls of buildings based on reaction to fire performance
- NFPA 285 and CAN/ULC-S134 as the North American full-scale equivalents
Related terms
Questions specifiers ask
Is BR 135 a test?
No. BS 8414 is the test method. BR 135 is the BRE classification document containing the performance criteria applied to the data that test produces.
What are the BR 135 pass criteria?
No external or internal level 2 thermocouple, 5 m above the combustion chamber opening, may record a temperature rise above 600 °C sustained for 30 seconds within 15 minutes of the start of test, and mechanical performance including collapse and falling debris is assessed.
Does a BR 135 pass satisfy the NCC?
No. Australia uses AS 5113, which has its own criteria including limits on flaming debris. A BS 8414 result can support an AS 5113 classification or a performance solution, but BR 135 itself has no standing in the NCC.
Does a BR 135 result cover a whole product range?
No. It applies to the specific system tested, including insulation, cavity width, cavity barriers, brackets and fixings. Any change requires reassessment or retesting.
Where was the ShapeShell-RT facade test done?
At BRE Global, where ShapeShell-RT passed the full-scale BS 8414 and AS 5113 facade test and met all AS 5113 criteria.
ShapeShell-RT passed the full-scale BS 8414 and AS 5113 facade test at BRE Global, meeting all AS 5113 criteria. See ShapeShell-RT specifications
Reviewed by Richard Halvorsen, General Manager, ShapeShift Technologies. Last updated September 2026.