BS 476-22:1987 – Non-Loadbearing Walls

Once you’ve booked a test, you can expect to receive a Test Date Booking Form – securing the booking date and agreeing the timeline for delivery and installation.

Closer to the time, we’ll ask you to complete a Customer Test Details Form, to confirm the exact details of the test. At this point we’ll also ask you to submit a full technical specification and CAD drawings in .dwg format.

The wall sample can be built by the test sponsor, or by our in-house build team – mechanically fixed within one of our 3m x 3m furnace restraint frames. During construction a member of our technical team will comprehensively document the materials and methods of construction.

If required, our in-house build team can prepare in advance an associated construction to reduce the size of the opening to suit your needs.

The sample is prepared for testing – measurements are taken, an array of thermocouples affixed, and positions marked for measurements to be taken during the test.

The frame is then mounted on the front of our 3m high x 3m wide vertical furnace so that one face of the sample is exposed to the fire – representing a compartment wall in practice.

The sample is evaluated for 2 criteria:

• Integrity – the ability to prevent the passage of flames and hot gasses
• Insulation – the ability to restrict temperature rise on the unexposed face

The result for each criteria is expressed as the number of whole elapsed minutes for which the sample maintains that ability.

Integrity is evaluated by:

• Sustained flaming, lasting at least 10 seconds on the unexposed face
• Opening of a gap, hole or crack which allows penetration of a 6mm or 25mm diameter gap gauge into the furnace
• Ignition of a cotton pad when held against the specimen in a wire frame holder for at most 15 seconds

Insulation is evaluated by:

• Average temperature rise: The thermocouples at the geometric centre of the sample and the centre of each quadrant are considered. The average temperature of these 5 thermocouples must not rise more than 140°C above its initial value.
• Maximum temperature rise: Of the array of thermocouples applied, the temperature of any individual thermocouple must not rise more than 180°C above the initial value of the average thermocouples.
• A handheld roving thermocouple is also used to evaluate for maximum temperature rise when needed.
• Failure to maintain Integrity constitutes a failure to maintain Insulation.

Irradiance and lateral deflection are also measured and reported against the total number of elapsed minutes.

• Same-day confirmation of test results by email and/or phone.
• On request, a link to the video of the test and any required intermediate reporting of test observations and data.
• A comprehensive Test Report. This is a multi-page document detailing the test results, test data and a breakdown of the assembled components including photos and drawings.
• There is no “Test Certificate” available, this is a misnomer. Testing and Certification are separate processes.
• The Test Report may be used by a third party for product assessment, there is no automatic extension of scope available within this test standard.

• The construction of the test specimen should represent the element in practice.
• Symmetry, and direction of fire exposure. Is the construction symmetrical through its thickness? If not, it may need to be tested from each direction.
• Are there any services to penetrate the system in practice? They may not be able to be added without further testing. See our Penetration Seals page.
• Amendments to Approved Document B (Fire Safety) will remove national classes using the BS476 series of standards as a method of demonstrating compliance, coming into force in September 2029. Contact us if you would like to discuss the effects of these amendments.