New DBI Fire Test with a 200 kg lead ball

Three powerful impacts after the classification test are part of DBI’s new fire test, the Impact Test. This test is used for walls in industrial and warehouse buildings, where there may be an increased requirement for wall robustness in the event of a fire.

In the Danish building regulations (BR18), the classification ‘Heavy BS Building Component 60’ and the equivalent European EI60 M classification are specified as functional requirements. This classification is typically used for walls in industrial and warehouse buildings where extra robustness is needed. BR18 also includes an EI120 M classification, which applies to industrial and warehouse class 5 buildings where storage exceeds 8.0 meters in height.

Now, DBI can perform the M-test alongside traditional fire resistance tests. The test consists of a standard classification test according to EN 1364-1, lasting either 30, 60, 90, or 120 minutes. As part of the M classification, a mechanical impact test is conducted, subjecting the structure to three powerful blows within five minutes after the fire test.

These impacts are delivered using a 200 kg lead ball swung into the center of the structure. The weight, speed, and impact location are determined by the EN 1363-2 standard. The purpose of this test is to evaluate whether the structure can withstand mechanical horizontal impact or shock after a fire.

– The test can also be used to document lightweight walls, such as aerated concrete or panel-clad walls, which are not covered by the technical regulations. The technical regulations state that heavy walls generally meet the M requirement if they are built with materials such as concrete or masonry. According to DBI, this remains common technical knowledge, says Christian B. Andersen, Head of DBI’s Fire Testing Department.

First customer test conducted

At the end of 2024, DBI conducted the first Impact Test for a customer, testing a wall made of clay boards, biogenic insulation, wooden beams, and an OSB chipboard.

– Everyone was naturally very eager to see the results. First, the 60-minute classification test had to be passed, and then the wall had to withstand the three impacts without cracking and allowing flames to break through, says Christian B. Andersen.

– Fortunately, the test went very well, and the wall passed without any issues. Therefore, we extended the test by another 30 minutes, providing the customer with documentation for a 90-minute test. Stronger documentation can be valuable in the fire strategy for the building where the structure will be used.

After 90 minutes, the test was stopped, and the furnace was opened. Parts of the clay boards had fallen off due to the three impacts, and the fire had penetrated deeper into the structure, but the test was passed because no flames broke through to the outside of the wall.

Test can be used for assessment

DBI’s horizontal furnace, used for the test, is 4.5 meters high and 3.2 meters wide. In practice, walls with an M requirement are typically higher than 4.5 meters. If documentation is needed for taller constructions, DBI can provide a fire-technical assessment based on a fire test.

– The wall we tested was only attached on one side during the test, meaning it can be built wider within the same classification. However, if an increase in height is required, a new classification test is generally needed, says Christian B. Andersen.

– In this case, that is not possible because the full height of the furnace was already used for the test specimen. If a taller construction is desired, we can instead offer a fire-technical assessment that can serve as documentation for an EI60 classification. The extra 30 minutes in this test positively contribute to the assessment of whether a taller wall would have the same fire resistance as an EI60-M classified wall. The assessment is based on our general fire testing experience, the test results, and our laboratory accreditation, he explains, adding that it is still uncertain whether an assessment will be necessary in this specific case.

Watch the Impact Test at DBI: