Structural Fire Engineering

Structural steel fire protection is an important issue and care should always be exercised to ensure that it is correctly specified

Fire protection does have an important role in life safety, but only during the first 30 minutes (possibly extending toward 60 minutes in the case of very high rise structures) and has a significant role in property protection beyond these periods. Whilst building codes legislate for extended periods of fire resistance, occupant life safety is rarely the issue at these longer durations.

The ability of a material to provide fire protection to an element of structure is quantified by furnace testing in conjunction with the determination of an extended field of application giving the dry film thicknesses (dft’s) for the range of durations, thereby allowing the product to be used easily by the design fraternity.

The testing is fairly standardised performing tests to BS476: Part 20 and Part 21: 1987, or more recently EN13881-4, but the development of the field of application can be approached in a number of ways. However, as there are at least 3 interdependent variables; section modulus, protection thickness and fire resistance duration, the characterisation process can be very complex.

However, IFC would stress that when the dft’s are engineered to achieve the level of fire safety required it is important that site practice ensures that these levels are applied.

For further information and professional independent advice on the engineering validity of data presented and the necessity to undertake additional fire testing to determine the dft’s please contact us.