What is BS EN 1365-1?

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Read our blog below and watch the video above to learn more about BS EN 1365-1, don't forget to test you've understood everything by taking the short quiz afterwards.
BS EN 1365-1: 2012 is a European testing standard for assessing the fire resistance  of loadbearing internal and external walls. It is used in conjunction with BS EN 1363-1: 2012. Test results obtained for specimens assessed under BS EN 1365-1 are classified to BS EN 13501-2:2016.

How are walls tested under BS EN 1365-1?

For the test, a representative wall specimen (typically full sized) is constructed in a test frame. The frame is designed to allow mechanical, hydraulic or deadweight loading approximating the structural load the wall will receive in its final application.

A gas fired furnace is used to expose one side of the specimen to heat. During the test, the average temperature of the furnace is monitored through thermocouples (temperature sensors) within the chamber and is controlled to follow a heat curve.
For separating elements (elements intended for use in separating two adjacent areas of a building in the event of a fire) which are required to be fire resisting from both sides, two specimens are tested separately (one for each direction). If testing is carried out from only one side, either due to the fact that the separating element is symmetrical on both sides or because it is only required to resist fire from one side, this shall be stated in the test report.

Different boundary conditions may require additional test specimens.

The test commences when any of the temperatures measured on any of the furnace thermocouples exceeds 50 degrees Celsius.  

Performance Criteria         
Throughout the test, the specimens are assessed for loadbearing capacity, integrity and insulation.

Loadbearing capacity
During the test, the height of the specimen is monitored. Any decreases in height (axial deflections) are recorded negatively.
The specimen is deemed to fail when it can no longer support the load. For vertically loaded walls this is the point at which the following criteria are met:
  • limiting vertical contraction (negative elongation), C = h/100 mm; and
  • limiting rate of vertical contraction (negative elongation), dC/dt = 3h/1000 mm/min.

(Where h is the initial height in mm).

The loadbearing capacity is then recorded as the number of complete minutes before failure.

Throughout the test any gaps or cracks are carefully monitored, and a cotton pad is applied at least 30 mm from the specimen for 30 seconds or until ignition.

The test specimen is deemed to fail when either:
  • the cotton pad ignites (defined as glowing or flaming); or
  • a 6 mm gap gauge can pass straight through a gap in the test specimen (so that its end projects into the furnace) and can be moved a distance of 150 mm along the gap; or
  • a 25 mm gap gauge can be passed through the specimen and project into the furnace; or
  • sustained flaming is visible.

The minutes completed prior to failure are recorded.

The temperature of the unexposed side of the wall is monitored with a number of fixed thermocouples and a roving thermocouple which can be moved to apparent ‘hot-points’ on the wall.
Failure is deemed to occur when either:
  • the average temperature recorded on the thermocouples rises above the initial temperature by more than 140 degrees Celsius; or
  • the temperature increase recorded at any of the thermocouples rises above the initial temperature by more than 180 degrees Celsius.

The minutes completed prior to failure are recorded.

The final result for each performance criteria is given as a time in minutes. The times for insulation and integrity cannot be longer than for loadbearing capacity. Similarly, the time for insulation cannot exceed that of integrity.

The results of the test can be applied to similar constructions with one or more of the changes listed below (known as the field of direct application of test results) providing they still comply with the appropriate design code for stiffness and stability.

Decreases in:
  • height;
  • stud spacing;
  • distance of fixing centres;
  • applied load or linear dimensions of boards; and/or
  • dimensions of panels (but not thickness).

Increases in:
  • thickness of the wall and/or component materials;
  • number of horizontal joints when tested with one joint not more than 500 mm (+/- 150 mm) from the top edge; and/or
  • width provided that the specimen was tested at full width or 3 m wide (whichever is larger).

BS EN 1365 Tested Kingspan Systems

Kingspan Kooltherm K12 Framing Board has been tested as part of a system under BS EN 1365-1: 2012. Full details of the test results are available within the product literature.

You can download the full testing standards from the British Standards Institution shop:
BS EN 1365-1:2012 - Fire resistance tests for loadbearing elements. Walls
BS EN 1363-1:2012 - Fire resistance tests. General requirements