In order to meet passive structural steel fireproofing code requirements, there are a number of methods available. 

The most common fireproofing method in the United States is to apply a spray-applied fire-resistive material (SFRM). Typical SFRMs are composed of cement and gypsum and may contain other materials such as mineral wool, quartz, perlite or vermiculite. The fireproofing is applied as either a wet or dry spray, or may also be troweled on to the required thickness. 

SFRMs are typically used when fireproofing steel beams or columns. While not its primary use, SFRMs may also provide an added benefit in the form of acoustical or thermal insulation. 

However, SFRMs are not usually suitable for surfaces with high exposure to moisture or humidity, which can deteriorate the product. This can make it difficult to use in areas with high humidity or where there are freeze-thaw cycles. Most SFRMs provide little to no independent corrosion inhibition for steel elements and other relative protection must be provided. The surface preparation (blasting, primers, lath/attachments, etc.) for most SFRMs can be costly and time-consuming.

Intumescent fire-resistive material (IFRM) coatings are another fireproofing material for structural steel. A thin layer of an epoxy-based mixture is applied to the surface. When heated, this coating chars, foams and expands — up to 100 times its original thickness — creating a barrier between the steel element and the fire. 

One of the benefits of intumescent paint is its lightweight characteristic and its corresponding ability to be used on exposed steel surfaces, without compromising design. 

However, intumescent products are highly vulnerable to environmental exposure during the application, which can limit their performance. The cost of intumescent coatings is also much higher than other options, with the cost increasing the higher the fire rating required.  

Intumescent products typically contain inherent corrosion inhibition for steel elements.  The surface preparation (blasting, primers, lath/attachments, etc.) for most IFRMs can be costly and time-consuming.

Rigid Board Fireproofing involves installing a rigid fire-resistive board to beams, columns and deckings. Rigid board fireproofing can be used in out-of-sequence construction phases so that it can be installed “as-you-go.” Rigid board fireproofing can also be used in many environments, including places with freezing weather conditions and with a variety of substrates. 

However, rigid board fireproofing tends to be a more expensive and slow to install option, which can impact tight project budgets and timelines. Rigid board fireproofing provides no independent corrosion inhibition for steel elements and other relative protection must be provided (blasting, primers, galvanizing, corrosion-resistant paints, etc.).

Flexible blanket systems offer combined fire, thermal and acoustic insulation and produce no toxic smoke at high temperatures. They are a lightweight and versatile product that can be easy to install even on complex shapes.

However, there is no customization available with flexible blanket systems — the product thickness is set by the manufacturer. The products also require additional fasteners as part of the installation. Finally, there are limited manufacturers of these products. 

Flexible blanket systems provide no independent corrosion inhibition for steel elements and other relative protection must be provided (blasting, primers, galvanizing, corrosion-resistant paints, etc.).

Concrete and masonry used to be one of the most common methods for fireproofing structural steel. These days, Portland concrete is mainly used to encase large areas of steel such as when fireproofing steel columns. 

However, traditional concrete fireproofing of structural steel requires a larger volume of space, has a high carbon footprint and is not design-friendly. Portland concrete fireproofing provides little to no independent corrosion inhibition for steel elements and other relative protection must be provided (blasting, primers, galvanizing, corrosion-resistant paints, etc.).