Introduction
Fire safety is a critical consideration in commercial and residential construction. When specifying stair formwork and void forms, clients often ask: “How does galvanised steel perform in a fire?”
The answer is reassuring. Steel is non-combustible, but its performance under fire conditions depends on factors such as temperature, duration, and loading.
The Science: Melting Point and Structural Integrity
The melting point of steel ranges between 1370°C and 1550°C—far exceeding temperatures typically reached in building fires. However, structural performance can be affected at lower temperatures due to loss of strength.
Our galvanised steel components have been tested to withstand up to 300°C for 30 minutes without significant effect on metallurgical properties. Beyond this, while some strength reduction may occur, the material remains in place and continues to provide a barrier.
Test Data: Proven Performance
We have subjected our products to rigorous fire testing:
- Five-Minute Fire Resistance Test: Galvanised steel passed with 166.5mm deflection observed. Some molten zinc was noted on the surface, but the structural integrity remained.
- Two-Hour Radiant Heat Test: Galvanised steel passed, confirming that our stair formwork and void forms provide up to 2 hours of fire resistance.
What This Means for Your Project
For commercial buildings, compliance with Part B (Fire Safety) of the Building Regulations is essential. Our products’ 2-hour fire rating ensures they meet the requirements for means of escape and fire compartmentation.
Additionally, our GRP grating for void forms is produced to Class B BS EN13501, superseding older BS476 standards, and has been tested for low heat release and flame spread.
Conclusion
When you specify Stair Formwork Ltd, you are choosing products that have been proven in fire tests. Safety is engineered into every component.
Need fire-compliant formwork? Contact our team for technical specifications.