Fire prevention measures and fireproof materials for steel buildings
Structural steel is a durable, noncombustible, fire-resistant material, but it can still be affected by high temperatures in a fire event. Therefore, building codes specify the number of hours a structure must withstand a given temperature, based on a variety of characteristics of the building in question. This is called the fire resistance rating.
Fire protection can be achieved through a combination of active and passive methods. Active fire protection consists mainly of sprinkler systems, gases or other means of automatically extinguishing the fire. Passive fire protection involves applying insulating materials to the steel members to prevent them from reaching critical temperatures.
Some common passive fire protection materials are:
Spray-applied fire-resistive material (SFRM): These are low-density fiber or cementitious compounds that form an insulating blanket around the steel when sprayed on. They are easy to apply and cost-effective, but they can be damaged by moisture or mechanical impact.
Intumescent coatings: These are epoxy-based, paint-like mixtures that expand to many times their original thickness when exposed to high heat1. They provide a smooth and attractive finish for architecturally exposed structural steel (AESS), but they are more expensive and require more quality control than SFRM1.
Board systems: These are rigid panels made of mineral wool, gypsum, calcium silicate or other materials that are attached to the steel with mechanical fasteners or clips. They provide a high level of fire resistance and durability, but they are bulky and labor-intensive to install.
The choice of fire protection method depends on several factors, such as the design requirements, the budget, the availability of materials and the environmental conditions.