Fire Resistance & Direction of Fire – Guidance for the Design and Construction Industry

This was one of the key lessons reinforced by the Grenfell tragedy. Steel-framed systems can behave differently from each direction, while single-acting doors may respond differently depending on whether they open towards or away from the fire.

Testing standard BS EN 1634-1 emphasises the need for dual direction fire resistance testing to ensure comprehensive fire protection.

Designers must satisfy themselves that the system they are specifying has the right form of fire test evidence or an assessment based on dual direction fire testing to ensure that it can meet compartmentation requirements.

In the remainder of this piece, I will outline what dual direction fire testing is and identify the importance of accurate dual direction fire test evidence and assessment to ensure designers are specifying products for the highest level of fire safety.

Understanding asymmetrical systems

Even seemingly symmetrical doors can become asymmetrical when intumescent seals, which are themselves not symmetrical, are used. These seals contain two reservoirs of intumescent material that react differently to fire and at various stages of fire development. Testing the seals in one direction alone does not accurately represent the door’s performance when the seals are oriented in the opposite direction. Therefore, it is crucial to test representative samples of the product family in both directions to ensure effective fire resistance.

Dual direction fire testing for steel-framed doors

Steel-framed doors are a critical component of fire protection systems. Testing standard BS EN 1634-1 requires doors to be tested in both directions to be classified for dual direction fire attack. In an example, a single leaf door opens away from the fire in the furnace, while the double leaf door opens towards the fire, exposing the meeting stile to maximum heat effects. This comprehensive testing ensures that the doors can resist fire regardless of the direction of fire attack.

Considerations for steel-framed fixed glazing

Similar to doors, steel-framed fixed glazing must also demonstrate its ability to resist fire from either direction. Testing standard BS EN 1364-1 allows for single direction fire testing if it can be proven to be the worst-case scenario. However, in such cases, the system should have an Extended Application Report (EXAP) or Field of Application Assessment from an accredited body to confirm its fire resistance capabilities.

Importance of dual direction fire testing

Designers and construction professionals must ensure that the systems they specify have the appropriate fire test evidence or assessments based on dual direction fire testing. This ensures that the systems can effectively meet the compartmentation requirements and provide comprehensive fire protection. By testing representative samples in both directions, the industry can ensure the safety and integrity of buildings in the event of a fire.

The Grenfell tragedy has underscored the significance of dual direction fire testing for passive fire protection systems. To prevent further tragedies, it is vital for designers to satisfy themselves that the system they are specifying has the correct form of fire test evidence based on dual direction fire testing as it ensures that it can meet the compartmentation requirement. The way to put your mind at ease is to demand to see the evidence and understand it. If a supplier can’t or won’t provide it, you need to ask yourself why?