Fireproofing Materials for Steel, Concrete, and Wood

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Fireproofing is an important part of building safety. In this guide, we’ll cover the different types of fireproofing and discuss which options make the most sense for your facility. Read on to learn more!

What is fireproofing?

Fireproofing is the process of making a material or structure fire-resistant. This can be done by applying a fire-resistant material, such as mortar, cement, or fireproof paint. Fireproofing is often used on steel structures and concrete to make them more resistant to fire.

There are two main types of spray-applied, fireproof paint: intumescent and cementitious.

Intumescent fireproofing swells when exposed to heat, creating a layer of insulation that protects the material or structure from fire. Cementitious fireproofing is a type of fireproofing that uses cement-based materials to create a fire-resistant barrier. 

Some examples of fireproofing include:

• Applying a fire-resistant spray coating to steel or concrete
• Using fire-resistant sealants, firestops, or fire barriers to seal gaps and openings (technically known as firestopping)
• Using fire-resistant building materials

Fire-resistant building materials are also typed of fireproofing. Examples of fireproof building materials include:

• Fire-proof glass
• Fire-proof doors
• Fire-proof insulation

Fireproofing is an important safety measure that can help to protect people and property. By making a material or structure fire-resistant, it can help to prevent fire from spreading and becoming more destructive.

Recommended fireproofing paint: Fire Barrier Paint

FlameOFF Coatings offers fireproof paint solution called Fire Barrier Paint.

Fire Barrier Paint is a low VOC intumescent paint that’s ASTM E-E84 and E-119 compliant.

This is a terrific solution for steel, wood, drywall, and other types of metal.

Fire Barrier Paint is the perfect coating for your next project. 

Fireproofing steel beams and structural steel

There are several methods that can be used to fireproof steel beams and structural steel.

One method is to apply a fire-resistant coating, such as intumescent paint designed for steel. Intumescent paint swells to a char that’s 100 times its original thickness when exposed to heat, creating a layer of insulation that protects the material from fire. These paints are non-toxic and are frequently used in steel exposed to the masses.

Another method is to use rigid board fireproofing. This type of fireproofing is made from rigid boards that are installed around the steel beam. Rigid board fireproofing is moisture-resistant and thermal insulated, making it an effective fireproofing method. 

Flexible blanket systems are more of a niche type of fireproofing for steel, but they offer a reliable, non-toxic barrier to prevent fire from rupturing the integrity of the steel. These systems meet nearly all safety codes, making them a very secure fireproofing method.

Concrete is the last common fireproofing method, but it is becoming less and less popular as time progresses. It is bulky, typically quite ugly, and requires a lot more space than other fireproofing methods to install, making it a hassle to deal with. However, concrete is quite a fire-resistant material for a few reasons.

Firestopping vs. fireproofing 

Fireproofing is the process of making a material or structure fire-resistant. This can be done by coating it with a fire-resistant material, such as mortar, cement, or fireproofing spray. Fireproofing is often used on steel structures and concrete to make them more resistant to fire, ultimately preserving the integrity of the underlying structure.

On the other side of the coin, firestopping is focused on sealing gaps and openings in a structure. This can be done with firestop bricks and mortars, composite sheets, and various sealants. Firestopping materials change shape during a fire, with many expanding in order to stop the spread of the fire, hence the name ‘firestopping’.

While both fireproofing and firestopping are important safety measures that can help to prevent fire from spreading, they are not the same thing. Fireproofing is used to make a material or structure fire-resistant, while firestopping is used to seal gaps and openings in a structure.

Fireproofing concrete 

Concrete is a fire-resistant material because it is non-combustible, non-toxic, and has low thermal conductivity. This means that concrete does not easily transfer heat, and does not react easily with other substances.

In the event of a fire, concrete can help to prevent the spread of fire by providing a physical barrier. Concrete can also be made more fire-resistant by coating it with a fire-resistant material, such as intumescent paint.

Another option is to apply a layer of lightweight mortar to exposed concrete surfaces. This helps to improve the fire resistance of concrete by providing a physical barrier and by insulating the concrete from heat. 

Board systems can also be used to protect concrete surfaces from fire. These systems are made from fire-resistant boards that are installed around the concrete. Board systems can be used to protect both internal and external concrete surfaces.

Fireproofing wood 

While wood is a combustible material, it is possible to make it more fire-resistant.

This can be done by coating the wood with a fire retardant or intumescent paint designed for wood. These types of paints slow down the spread of fire, and they can improve the fire resistance of wood.

Another option is to use fire-resistant sealants. These products are applied to the surface of the wood and they create a barrier that helps to prevent fire from spreading.

It is important to note that it is not possible to make wood fireproof. However, by using fire retardant products, you can make the wood more resistant to fire.

Many products exist on the market to offer improved fire ratings for different structural materials. FlameOFF Fire Barrier Paint does just that; it is an intumescent paint that can be applied to many building materials including interior steel, drywall, and even wood.

When to use spray applied fireproofing

Spray applied fireproofing is used as passive fireproofing for a building and is typically referred to as Sprayed Fire-Resistive Material (SFRM).

SFRM is a cement or mineral-fiber-based fireproofing material (e.g. gypsum) that is applied as a spray to steel beams and columns. As mentioned earlier, it is sometimes used on concrete to provide a fire-resistant barrier.

SFRM is typically used in commercial and industrial buildings. It is often used in combination with other fireproofing products, such as intumescent paint to up fire resistance further. It is best used on surfaces that are not exposed to moisture or high humidity levels. For example, some practical applications include large, open interior areas like parking garages or auditoriums.

On the regulations side of things, structures that have had SFRM applied are regulated by the ASTM E-119 Standard Test Methods for Fire Tests of Building Construction and Materials to determine fire resistance.

The ASTM E736, the Standard Test Method for Cohesion/Adhesion of Spray Fire-resistive Materials Applied to Structural Members is also the main code that determines the characteristics of SFRM.

How to spray fireproofing 

The United States NFCA, the National Fireproofing Contractors Association, has established a set of guidelines detailing the proper application, preparation, repair methods, and safety issues regarding wet and dry SFRM types. These guidelines are broken down in the NFCA100 Standard Practice for the Application of Spray-Applied Fire Resistive Materials (SFRMs).

To avoid getting too jargony, let’s take a look at these guidelines and translate them into easy-to-understand terms.

Wet spray SFRM is typically applied with a pump and hose system. This SFRM is combined with water, forming a slurry. This slurry is then pumped through the aforementioned pump and hose system and is dispersed through a nozzle with air.

Dry spray SFRM, on the other hand, uses water differently. While a dry SFRM also gets sent through a pump and hose system, the dry spray is delivered through a hose and once it reaches the nozzle, atomized water is added to change the consistency of the spray. The mixture is then sprayed onto the surface in an even pattern; dry sprays are best used when weather conditions are poor.

A general rule to note is that it is important to apply SFRM evenly to the surface. Once it is applied, SFRM should be allowed to dry completely before adding any additional layers of fireproofing.

Types of fireproofing building materials

There are six types of fire-resistant building materials: flame-treated natural products, fire-resistant glass for windows, concrete, stucco, gypsum, and brick.

Flame-treated natural products

Flame-treated natural products are natural materials like wood or cotton that offer very poor resistance but have been treated with chemicals to make them more resistant. The main advantage of using flame-treated natural products is that they are often cheaper than other options. However, the downside is that they are not as effective as other options.

Fire-resistant glass

Fire-resistant glass is a type of glass that is designed to withstand high temperatures without breaking. The main advantage of using fire-resistant glass is that it can provide a very effective barrier against flames; many different types of glass offer different benefits, like dual-paned, glass blocks, and even wired glass. However, the downside is that most types of glass are more expensive than other options.

Concrete

Concrete is a very popular option for fire-resistant building materials. The main advantage of using concrete is that it is very effective at resisting fire, and it is also very affordable. However, the downside is that concrete can be very heavy and difficult to work with while also not being the most attractive material to work with.

Stucco

Stucco is a type of plaster that is commonly used in exterior walls. It is typically made with a mix of sand, lime, and cement and can be applied as a fire-resistant finish for virtually any structural material. This allows it to be an extremely versatile fire-resistant material, with the only caveat being that it can be a bit pricier than options like concrete.

Gypsum

Gypsum is a type of rock that is very popular in fire-resistant building materials. Most people know gypsum best as drywall, which is a layer of gypsum in between two thin sheets of paper. Gypsum, interestingly enough, has a noncombustible center that also contains calcium sulfate, a derivative of water. This means that upon a fire occurring, steam will emerge from the drywall, slowing the fire and effectively delaying the structural breakdown of the drywall. The issues with gypsum boards come in non-fire related problems: it is difficult to create curved drywall boards, and it is also quite brittle, meaning impacts are likely to damage the boards.

Brick

Last but not least, brick is a classic fire-resistant building material. Considering brick is literally baked in a kiln to create it, it is objectively one of the best materials on this list to resist fires. When combined with mortar to create a brick wall, its effectiveness lowers slightly, but it is still highly resistant. The downsides are a bit more than most would predict: brick is relatively expensive, it is very heavy, and it isn’t very good at insulation, meaning brick structures are not very energy-efficient.

Key Takeaways

There are a few core points that you should be walking away from this article understanding at a deeper level:

1. Fireproofing is the act of making a structure more resistant to fire, usually through the use of chemicals; paints like FlameOFF Fire Barrier Paint offer a significantly increased level of fire resistance
2. Firestopping stops a fire from spreading by expanding and disallowing it from moving to other areas
3. There are various methods for fireproofing steel, concrete, and wood, with spray-applied fireproofing (SFRM) being the most popular
4. There are six main types of fire-resistant building materials: flame-treated natural products, fire-resistant glass for windows, concrete, stucco, gypsum, and brick