Why Steel

Finishes, Coatings, and Fire Protection

Structural steel buildings perform well when exposed to fire

Steel is a durable, noncombustible, fire-resistant material.  When properly designed and constructed, steel framing can preserve its structural integrity in the event of a fire and exposure to prolonged elevated temperatures. The International Building Code (IBC) and other current building codes contain prescriptive criteria for determining when and what requirements apply for the various types of construction, heights, areas and occupancies.

Fire protection is accomplished through a combination of active and passive fire protection methods.  Many steel-framed structures, including some low-rise buildings, sports stadiums and open-deck parking structures, do not even require fire protection or only require active fire protection (sprinkler systems).  However, when passive fire protection is required there are several cost-effective coating options that can not only achieve a suitable fire rating, but also look attractive if the steel is left exposed.

Conventional Coatings (SFRMs)

  • Spray-applied, fire-resistant materials expand and insulate structural steel to prevent failure that can result from rapidly rising temperatures. 
  • Generally, SFRMs are available in two types: cementitious coatings and spray fiber coatings.
  • SFRMs are typically used if steel is hidden from view, such as above a room's ceiling or behind its drywall.

Intumescent Coatings

  • Intumescent coatings consist of thin chemical films that swell and expand when exposed to high temperatures to form a durable, adherent, fire-resistant foam layer.
  • Intumescents appear more paint-like when applied to structural steel, giving them greater potential for aesthetic and architectural applications.

Exterior Intumescent Coatings

  • Exterior intumescent coatings are used in heavy industrial environments or when steel is located on the outside of a building and still needs a fire rating
  • Exterior intumescents also serve well in locations with tight space restrictions like elevator shafts, where a thinner, alternative option to conventional cementitious fireproofing is desired.

In addition to coatings, a specified fire rating can be achieved with rated board, concrete-filled hollow structural section (HSS) shapes and concrete-encased, wide flange members.  To determine what fire rating and level of protection you need on your project, refer to chapters 6 and 7 of the IBC.

For more information about fire and fire protection see Facts For Steel Buildings - Fire


Still need help?

The Steel Solutions Center is for people who need technical assistance, innovative solutions, or tools to make structural steel design even easier.

Visit the Steel Solutions Center