What is ISO 13785-1?

  • Est Time: 10 mins
  • Rating: Artboard 1
ISO 13785-1:2002 is an intermediate scale reaction to fire test for façade systems. As with BS 8414, it is designed to simulate a fire beginning in a building, venting through the window and impinging on the façade. The test can be used for screening or evaluation of sub-components or “families of products”.

Research from Efectis has shown that ISO 13785-1 can be used to accurately assess the reaction to fire performance of façade systems against data from a control BS8414 large-scale test.

What happens in an ISO 13785-1 test?


The test is conducted on a rig comprising three 2.4 m wide outer walls: a main back wall with side walls at either end. A 1.2 m wide gas ignition burner is situated at the central base of the back wall with a 0.6 m side wall on one side. All walls are 2.8 m tall.

The test specimen is a section of façade which is representative of the system used in practice, complete with all joints and fixings. A 1.2 m x 2.4 m sample is mounted on the back wall with a further 0.6 m x 2.4 m section mounted on the smaller side wall. Both sections are installed 0.4 m above floor level.

Thermocouples (heat sensors) are placed on the face of the systems at distances of 0.5 m, 1 m, 1.5 m, 2 m and 2.4 m from the bottom of the samples. In systems with a cavity, additional sensors are placed within the cavity at 1.2 m and 2.3 m from the bottom edge.



During the test, the gas burner is ignited and burns at 100 kW for a period of 30 minutes or until the top of the specimen is extensively flaming.

Throughout the duration of the test the specimen is observed and time for occurrence are recorded for:

  • Ignition of the test specimen;
  • Flame spread to 0.5 m, 1 m, 1.5 m, 2 m and 2.4 m on the specimen; and
  • Any flames emerging from the cavity behind the specimen.
In addition, measurements from the thermocouples are used to provide information of fire spread across the rig and within any cavity. The following measurements are recorded:
  • Heat flux as a function of time in a graph;
  • Thermocouple temperatures as a function of time in graphs; and
  • Maximum value of heat flux.

You can download the full testing standard from the International Organization for Standardization: