What is spray-applied fire-resistive material (SFRM) used for in structural steel construction?

• A. Provides fire resistance to structural members; applied to beams and columns as fireproofing.
• B. Increases the thermal conductivity of steel.
• C. Acts as a decorative coating.
• D. Waterproofs concrete.

Answer: (A)

Spray-applied fire-resistive material is used to protect structural steel by serving as an insulating fireproofing layer. Steel loses strength quickly at high temperatures, so exposing beams and columns can lead to rapid deformation and collapse during a fire. By applying SFRM to beams and columns, heat transfer to the steel is slowed, allowing the members to maintain their strength for a required period as specified by the fire-resistance rating. This helps preserve the structural integrity of the frame long enough for occupants to evacuate and for firefighters to respond. The material is typically cementitious or cement-based and is chosen to meet building code fire-rating requirements.

It doesn’t increase the steel’s thermal conductivity; it actually impedes heat flow. It isn’t used for decoration, and it isn’t a waterproofing coating for concrete.