BS 476 vs EN 1364: understanding fire-testing standards

BS 476 and EN 1364 are important standards for fire safety in construction. Find out what they mean for your project.



In the UK, fire-testing standards are an essential consideration in any construction project.

Their purpose is simple: to prove building materials will minimise harm to people and property in the event of a fire. No guesswork – just cold, hard science.

This elimination of guesswork means you can be sure your project is compliant with local and national safety legislation. So, as well as keeping people safe, it safeguards your reputation.

In practice, fire-testing standards improve containment. This means fire doors, glazing, walls and other essential components can contain a fire for a fixed time period.

In doing so, the so-called "evacuation window" is increased. The spread of flames and toxic gases is impeded, giving people more time to leave and firefighters more time to respond.

In the UK, fire-testing standards are spread across different documents. Two major documents are BS 476 and EN 1364.

What are the differences – and why do they matter?

What are the key differences between BS 476 and EN 1364?

The main difference is that BS 476 consists of British fire-testing standards, whereas EN 1364 is a European series specifically covering the fire resistance of non-load-bearing elements.

In other words, BS 476 covers a lot of ground, whereas EN 1364 is more specific. Conversely, BS 476 is only used in the UK, whereas EN 1364 is Europe-wide.

They also measure fire resistance differently.

How BS 476 tests work

BS 476 measures fire resistance by testing building elements inside a specialised furnace.

Parts 20 to 24 of BS 476 involve exposing construction elements like walls, floors and doors to extreme heat. Assessors then measure how long the construction element lasts before failing.

The test measures three main factors: load-bearing capacity, integrity and insulation.

1. Load-bearing capacity refers to a structural element's ability to support a load without collapsing.
2. Integrity (E) measures the element's ability to block flames, gases and smoke.
3. Insulation (I) measures its ability to restrict heat transfer.
   
   

How EN 1364 tests work

EN 1364 works differently. It measures fire ratings by testing non-load-bearing building elements: things like walls, ceilings and curtain walls.

A sample of the building element is put in a test frame and placed in a furnace. The test measures how many minutes pass before the assembly fails predetermined performance metrics.

The data from this test is then combined with EN 13501-2 to create a formal rating code. These are the letter and number combinations you see in product descriptions (EI60, E120 and so on).

There are four key performance metrics in the EN 1364 test:

1. Integrity (E): the non-load-bearing element's ability to restrict the spread of flames and hot gases
2. Insulation (I): its ability to limit heat transfer (tested by measuring direct surface temperature rise on the safe side)
3. Radiation (W): its ability to restrict the spread of thermal radiation (tested by measuring the outward transmission of heat into the surrounding space)
4. Mechanical action (M): its resistance to impacts and structural shocks
   
   

When would you use BS 476 or EN 1364?

Let's say you're testing the fire resistance of a non-load-bearing partition wall.

Under the older system, you might carry out fire resistance tests under BS 476-20 and BS 476-22. This will give you an integrity and insulation rating.

Under the newer, European route, you'd use EN 1364-1 to carry out a fire resistance test for a non-load-bearing wall. The resulting fire rating would be measured in the European way: EI60, E30 and so on.

Ultimately, BS 476 is the British fire-resistance test for walls, floors, doors and other structural components. EN 1364 specifically covers non-load-bearing elements.

For this reason, there's no simple equivalence to be drawn between the two tests. This means you shouldn't interpret a BS 476 result as being the same as an EN 1364 result.

What does BS 476 cover?

BS 476 consists of a series of tests to measure the fire rating of building materials and construction. The main parts are:

• BS 476-4: non-combustibility test for materials
• BS 476-6: fire propagation test
• BS 476-7: surface spread of flame test
• BS 476-20: general principles and procedures for fire-resistance testing
• BS 476-21: fire-resistance testing of load-bearing elements
• BS 476-22: fire-resistance testing of non-load-bearing elements
• BS 476-23: fire resistance of components in a ceiling system
• BS 476-24: fire-resistance testing of ventilation ducts
• BS 476-31.1: smoke penetration through doorsets and shutter assemblies
  
  

If a product is described as "tested to BS 476", you need to know which part of BS 476. "Tested to BS 476" doesn't automatically mean a 60-minute fire rating.

It could refer to a non-load-bearing wall (BS 476-22), a load-bearing beam or column (BS 476-21), the surface spread of flame (BS 476-7), and so on.

What does EN 1364 cover?

EN 1364 is a series of European fire-resistance test standards specifically for non-load-bearing building elements. These include interior partition walls, curtain walls and cladding.

The test determines how long one of these elements can resist exposure to fire while meeting performance standards.

Here are the main parts:

• EN 1364-1: non-load-bearing walls and partitions
• EN 1364-2: non-load-bearing ceilings
• EN 1364-3: curtain walling – full configuration
• EN 1364-4: curtain walling – part configuration
• EN 1364-5: air transfer grilles
• EN 1364-6: raised access floors
  
  

The essential point is that EN 1364 specifically covers non-load-bearing structural elements. If the element bears a load, it will need to be fire-rated under a different system.

Is BS 476 being phased out?

The BS 476 series is currently being phased out and replaced by European standards (BS EN). The final removal will take place in September 2029.

How does Approved Document B relate to these fire-testing standards?

Approved Document B tells you the level of fire performance needed to meet Building Regulations. BS 476 and EN 1364 provide tests to demonstrate fire performance.



Founded in 1996, Wrightstyle is a UK-based curtain wall manufacturer and supplier of specialist glazing systems. For more information on fire safety compliance, follow our blog or contact our team for expert product advice.