New Test Standard for Facades on the Rise
RISE coordinates the development of future common European methods for testing and classifying the fire behavior of building facades. Currently, there are 11 different standards for assessing facade fire behavior in Europe, presenting challenges and expenses for businesses with international ambitions. In response, the European Committee for Standardization (CEN) and The European Organization for Technical Assessment (EOTA) have collaborated to establish a joint, harmonized system for fire testing and classification of facades and external walls. The European Commission has funded the project “SI2.825082 Finalisation of the European approach to assess the fire performance of facades,” which aims to present a proposal accepted by all EU member states.
Project Coordination and Objectives
RISE coordinates this project, with the main objective of finalizing a harmonized methodology for fire performance testing within the European Economic Area (EEA). This work includes a theoretical round robin of the proposed method, initial testing to determine suitable tolerances for the fire source, and assessing the repeatability of the method. Repeatability testing has been conducted using the same testing equipment in the same laboratory to evaluate variations in outcomes. The final phase of the project involved a round robin with relevant façade systems widely used in the European Union.
Round Robin Testing
The round robin is performed by RISE in collaboration with five other test and research institutes across the EU. This entails carrying out the same experiments in different locations with the same type of specimen and test rigs built according to the specifications of the method. Participating institutes can then compare data and assess the reproducibility of the methodology, determining if it consistently yields the same results and identifying the necessary measurement parameters for future regulations.
Simplifying Regulations
The aim is for the industry to have a simpler and more uniform set of regulations. A common European testing and classification methodology will enable CE marking of façade systems, which can be achieved once the final methodology is completed by CEN. CE marking (CE = Conformité Européenne) signifies to public control authorities that the marked product meets applicable safety requirements in the EU and EEA area, allowing for free market access.
Comparison of Test Methods
At RISE, we have compared two different test methods: the Swedish SP Fire 105, long established in the Nordics, and the current proposal for a new EU standard facade test (Draft EU test). The Draft EU test can be conducted on both large and medium scales. The results from an SP Fire 105 test are primarily based on observations and assessments, while the Draft EU test emphasizes measurable criteria and sets tougher requirements for the fire performance of the outer wall.
In a large-scale Draft EU test, the facade must be built 2.5 meters higher than in an SP Fire 105 test and must include a return wing that radiates heat back to the front of the facade, potentially generating a chimney effect in the corner. Current testing indicates that products passing the SP 105 test may not pass the future EU test, whereas most specimens assessed by other large-scale methods perform well in the Draft EU test.
Study of Façade Test Methodologies
To further investigate these differences, a study titled “Comparison of Two Test Methodologies for Fire Testing of Façade Systems” was conducted, performing two fire tests on the same façade system. Both tests took place in RISE’s large fire test hall in Trondheim, Norway. Thermocouples measured temperatures, while the visible flame height and behavior of the façade system were visually observed and recorded. The façade construction consisted of a stone wool insulated framework, a ventilated cross-lathed cavity with vertical and horizontal battens, and a 21 mm vertical wood cladding.
Fire damage of the surface of the façade after the test according to SP Fire 105 and according to the draft proposed European method. The black horizontal segments indicate an external fire barrier that was part of the tested façade design.
Results from SP Fire 105 Test
The test according to SP Fire 105 lasted for 21 minutes and 45 seconds from ignition until the fuel burned out, fulfilling the test’s performance criteria. The fire source in the SP Fire 105 method is a heptane pool fire with a wide and narrow opening, yielding a maximum heat release rate of less than 3 MW.
Principle drawing of the test rig showing dimensions for the draft proposed European method façade, alongside the SP Fire 105 rig. Both rigs are shown at a 1:1 scale and aligned with the top of the fire room and combustion chamber for size comparison.
Results from the European Test
In contrast, when tested according to the draft European test method, the full length of the test specimen’s surface ignited after 16 minutes and 15 seconds. After 30 minutes, the fuel (a timber crib) required extinguishing with water, and the test concluded after 35 minutes by spraying the façade surface with water. The draft EU method uses a wood crib weighing approximately 350 kg with a quadratic opening (2m x 2m), resulting in a higher peak heat release rate of more than 3.5 MW for an extended period compared to the SP Fire 105. Additionally, the method includes a return wing with a minimum width of 1.5 meters, creating an internal corner that increases temperature and intensifies the chimney effect.
Performance Criteria
While the draft proposal for the European test does not specify performance criteria, the significant damages observed suggest that this façade system is unlikely to pass any upcoming performance criteria.
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Mikael Bergius
mikael.bergius@risefr.no
Johan Anderson
johan.anderson@ri.se
