Steel is a well-known material for its strength and durability in architecture and construction projects. However, steel’s susceptibility to high temperatures and fire is a significant challenge. This is where intumescent coatings come into play as a critical solution for enhancing the fire resistance of steel structures. These coatings, also known as intumescent paints, are a simple and effective way to protect the essential parts of a building, like columns, beams, floors, and roofs, from fire.
This coating helps keep the building from collapsing during a fire by insulating these structural elements. It provides the building with a certain amount of time to resist fire, which is crucial for safety. In this blog, we will discuss how they work, their applications, and considerations for use in construction. Let’s discuss it in detail!
How Is Intumescent Coating Applied?
Intumescent coatings are generally applied in three layers: a primer, a base coat, & a top coat. The primer helps the coating stick well to the metal and provides extra protection against rust. The top coat is sometimes added for looks or to make the coating last longer, especially in harsh weather or environments. Before applying it, the metal surface must be well-prepared and cleaned to remove any dirt or grease, creating a rough texture that helps the fire resistant coating stick better.
Nowadays, steel parts are often coated using an airless spray, a quick method that works well even on uneven surfaces. Brushes and rollers can also be used for application. Getting the coating thickness right on steel sections is tricky and depends on various factors like temperature and humidity. It’s important always to check the finished job’s quality and ensure it has the minimum thickness needed.
How Do Intumescent Coatings Work?
Steel’s critical temperature, defined as the point at which its load-bearing capacity is compromised by heat, typically ranges from 500 °C to 620 °C. However, this temperature can vary between 350 °C and 750 °C, depending on the structural loading conditions. This is why these coatings are particularly crucial for buildings with load-bearing steel elements, which can fail when exposed to high temperatures.
Upon exposure to heat, intumescent paint swells significantly, increases the volume of the fire resistant coating, and decreases its density, forming a ‘char’ layer that insulates the steel from the effects of the heat. These coatings are typically composed of three main components:
Binder: The component that forms the film and binds the other ingredients to the steel surface.
Flame Retardant: Generally, a phosphate that reacts to heat and forms a char.
Carbonific: A source of carbon that chars upon heating, contributing to the foam-like, insulating layer.
What Are the Factors to Consider for Intumescent Coatings for Steel?
When selecting and applying these coatings, it is important to consider various key factors to ensure optimal performance and compliance with safety standards. Below are some detailed considerations for choosing and using intumescent paints on steel frameworks.
Types of Coating
Intumescent coatings come in various formulations, each with specific characteristics suited to different conditions and requirements:
Water-based Coatings: These are environmentally friendly options that emit lower volatile organic compounds (VOCs) and should be lower than 36gr/liter. They are ideal for indoor applications where air quality is a primary concern after wildfires. These coatings are non-toxic and don’t create any fumes. Additionally, these coatings are ideal for industrial properties or areas requiring maximum durability and fire protection.
Solvent-based Coatings: These coatings typically offer better adhesion and durability in harsh environments. They are well-suited for exterior applications or areas with significant chemical exposure or varying temperatures. However, they do emit higher levels of VOCs compared to water-based alternatives.
Epoxy-based Coatings: These types of coating are known for their robust protective qualities. Epoxy-based intumescent paints provide excellent heat resistance and structural strength. However, a major disadvantage of solids-based epoxy is its extremely short pot life.
Thickness of Coating
The required thickness of intumescent paint depends on several factors:
Steel Section Size: The size and complexity of the steel sections play a crucial role in determining the thickness of the coating. Larger or more complex structural elements often require a thicker layer of intumescent paint to ensure they are well protected in a fire. The surface area exposed to heat and the volume of metal that needs to be insulated both influence the required thickness.
Fire Resistance Rating Desired: The thickness will also vary depending on the fire-resistance duration required (1-2 hrs generally). The longer the protection period required, the thicker the paint must be applied. This ensures that the steel beneath can withstand fire exposure without reaching its critical temperature for the duration specified. The coating manufacturer provides these specifications and must align with regulatory fire safety standards.
Assessment and Testing: It is important to refer to the technical datasheets provided by the paint manufacturers, which detail their products’ performance characteristics and application requirements. You can also consult with fire safety engineers for your construction project. These professionals can evaluate your project’s specific conditions and recommend the appropriate thickness based on empirical data and performance tests.
Compliance and Standards
Before applying these coatings, they must adhere to the following safety standards:
LEED v4–Compliant Paints: For projects aiming for LEED certification, selecting LEED v4–compliant intumescent coatings can contribute to earning points under the Indoor Environmental Quality credit category. These paints are specially formulated to lower volatile organic compound (VOC) emissions, improving environmental quality and occupant health.
ASTM Standard Testing: Adhering to ASTM standards for intumescent coatings is essential for ensuring high-quality fire protection and environmental safety. The ASTM standards establish critical benchmarks for the performance of fireproofing materials, offering a reliable measure of their effectiveness. By adhering to these standards, intumescent paints provide assurance regarding their fire-resistant characteristics and adherence to safety regulations. This builds trust among stakeholders and enables the creation of more resilient building solutions.
Wildland-Urban Interface (WUI) Compliance: In regions vulnerable to wildfires, particularly in the Wildland-Urban Interface (WUI), using intumescent paints that meet specific WUI regulations is important for enhancing building safety. These coatings are designed to resist the spread of fires from adjacent vegetation and natural areas, providing an additional layer of protection for structures in these high-risk zones.
Conclusion
By applying intumescent coatings, buildings benefit from an added layer of protection, substantially increasing their ability to withstand fire without structural failure. This not only ensures a higher degree of safety for occupants but also helps preserve the integrity of the building’s critical components during emergencies. At Firefree Coatings, we are committed to providing the most trusted intumescent coatings that are LEED v4 compliant and meet different ASTM standard requirements. Our products undergo rigorous testing, including Room Corner Tests, to ensure our coatings deliver unmatched protection and performance under extreme conditions. Call Us Today!
Intumescent coatings are specialized fire-retardant coatings designed to expand when exposed to heat or flame, forming a thick insulating layer. This layer protects the substrate beneath, generally steel or wood, from the effects of fire, thereby significantly delaying its structural failure.
Intumescent coatings are beneficial for everyone, especially for those who live in Wildland Urban Interface zones. These fire retardant coatings are generally applied alongside a primer and a topcoat to provide corrosion protection and aesthetic customization. In this blog, we are going to discuss what exactly these coatings are and how they are used in various applications.
How Do Intumescent Coatings Work?
Upon exposure to fire or excessive heat, intumescent coatings activate a vital protective mechanism. The heat triggers a chemical reaction within the coating, causing it to expand significantly. This reaction involves the release of non-flammable gasses, such as ammonia or carbon dioxide, which form a foam-like layer.
This expanded layer acts as an insulating barrier, increasing in thickness—often up to 50 times its original size. The resultant thick, charred layer effectively absorbs and dissipates the heat, slowing down the fire’s spread. This char layer serves as a thermal barrier, protecting the material or structure from the intense heat of the flames.
Are There Different Types of Intumescent Coatings?
Each type has distinct compositions and applications based on their environmental resistance, drying time, and durability:
Water-Based Intumescent Coatings
These coatings are characterized by their environmentally friendly attributes, primarily due to their water-based composition, which minimizes harmful emissions and reduces odors. They are typically more cost-effective than other types.
However, their main limitation is a longer curing time, especially in environments with high humidity or low temperatures. This makes them most suitable for indoor use where extended curing periods won’t pose a significant issue. Their application is ideal in settings where rapid drying is not critical, such as in non-urgent maintenance or refurbishment projects.
Solvent-Based Intumescent Coatings
Designed for robust performance in varied environmental conditions, solvent-based coatings are preferred for their ability to withstand weather and temperature fluctuations. They dry relatively quickly and provide a smooth finish, characteristics that make them highly suitable for semi-exposed areas.
These areas might include partially sheltered structures yet still vulnerable to climate variability. These coatings’ rapid drying and durable nature make them ideal for use where protection from the elements and quick project turnaround are prioritized.
Epoxy-Based Intumescent Coatings
These are the most resilient among intumescent coatings, specifically engineered to perform in extremely harsh environments, such as offshore platforms, marine settings, and chemical processing plants.
Epoxy-based coatings are excellent in protecting against hydrocarbon fires and offer significant resistance to corrosion. They are generally applied in a two-part process that forms a thick, robust film that effectively insulates structural steel elements from intense heat and fire damage when cured.
What Are the Key Ingredients of Intumescent Coatings?
Intumescent coatings are well-known for their fire-resistant capabilities. But what exactly makes these coatings fire-retardant? Let’s discuss its key ingredients in detail!
Ammonium Polyphosphate
This ingredient plays an important role in the fire-retardant properties of intumescent coatings. At high temperatures, usually around 600°F (316°C) or more, Ammonium Polyphosphate breaks down into two substances: ammonia and polyphosphoric acid. This breakdown process helps to release water vapor, which contributes to the expansion of the coating when exposed to fire.
Melamine
This is another essential ingredient in intumescent coatings. When temperatures rise to around 340°F (171°C), Melamine starts to decompose. This decomposition process produces ammonia, carbon dioxide, and water. These gasses aid in the expansion of the coating and insulate the surface from the heat of the fire.
Pentaerythritol
Unlike Melamine, Pentaerythritol has a lower temperature threshold for decomposition, typically around 190°F (88°C). When exposed to heat, Pentaerythritol decomposes into aldehydes, which further contribute to the formation of the protective char layer.
Titanium Dioxide
Normally known as a white pigment used in paints, Titanium Dioxide remains chemically inert at room temperature. However, when exposed to high temperatures, usually above 1800°F (982°C), this undergoes a phase change and melts. This molten Titanium Dioxide binds with the polyphosphate, enhancing the overall effectiveness of the intumescent coating.
How Long Do Intumescent Coatings Last?
Intumescent coatings, designed to provide fire resistance, have a lifespan that can vary significantly from 5 to 50 years, depending on several factors, including the specific formulation and the application conditions. As the manufacturer recommends, these coatings require regular maintenance and periodic recoating to retain their effectiveness.
When properly maintained, these coatings can protect the underlying material from heat and flames for a duration that typically ranges from 30 to 120 minutes. This is measured according to their ASTM fire rating, indicating how long the material can withstand flames while effectively resisting the heat. This feature makes intumescent coatings an important component in enhancing the fire safety of buildings and structures.
Key Considerations in Intumescent Coating System Selection
Several key considerations exist when selecting a fire retardant coating system for your building. Some of them are listed below:
ASTM Standards and ICC Compliance
The intumescent coatings should meet ASTM standards for fire and weather resistance. This system should also meet the criteria set by the ICC Evaluation Service, which confirms its suitability for use in areas vulnerable to wildfires, as outlined in the California Building Code Section 704A.
Lower VOCs
Intumescent paints offer significant ecological benefits by emitting lower levels of VOCs (volatile organic compounds) than traditional fire protection methods. This helps reduce the carbon footprint and minimizes the risk of harmful emissions during a fire, enhancing your safety.
LEED v4–Compliant Paints
The fire retardant coating system should preferably be LEED v4-compliant, ensuring that it meets the standards set by the LEED rating system for green building certification. Using LEED-compliant paints contributes to sustainable building practices, enhances indoor air quality, and promotes occupant health and well-being.
Conclusion
Intumescent coatings are essential for fire safety, creating protective layers when heated to shield materials such as steel or wood. This blog has covered their mechanisms, variations, components, durability, and factors for choosing them. It highlights their indispensable contribution to enhancing fire protection in diverse properties and emergencies.
Firefree Coatings is a leading provider of intumescent coatings, offering solutions tailored to various needs and environments. With a focus on safety, durability, & environmental responsibility, we ensure optimal protection against fire hazards while adhering to industry standards and regulations. Call us and make an order today!
Fire safety is an important factor to consider in building design and construction. Whether it’s for commercial or residential properties, ensuring protection against fire hazards is an essential step. Fire retardant Coating (Class A), certified by ASTM E84, is a solution that has become popular among many for enhancing fire resistance.
However, wildfires are a common concern among many, especially if you live in wildfire-prone areas in the US. According to the National Interagency Fire Center (NIFC), 5,260 fires burned 1,659,645 acres from January to March, which averages to 315.52 acres burned per fire.
This shows the significant scale and impact of wildfires, underscoring the importance of these coatings in reducing the destruction they cause. But how do these coatings work & why is this testing standard needed? Well, in this blog, we are going to discuss the same.
What is ASTM E-84 for Fire Retardant Coating?
Intumescent coatings, especially those classified as Class A according to ASTM E-84, play a vital role in enhancing the safety and compliance of your project. But what exactly is ASTM E-84, and how does this safety standard ensure compliance in application? The ASTM E-84 test, developed by the American Society of Testing and Materials, is a crucial evaluation that measures the burning characteristics of materials.
It specifically provides comparative measurements of surface-level flame spread and smoke density, which are essential for assessing fire safety. The development of fire tests such as ASTM E-84 was spurred by historical fires highlighting the need for better safety standards, such as the devastating 1942 Cocoanut Grove nightclub fire.
This test is widely applicable across various industries, particularly in projects that involve building renovations, maintenance, or new developments. Ensuring materials like paints or intumescent coatings meet the safety standards set by the ASTM E-84 test is integral to project compliance and safety. According to the International Building Code, this test is mandatory for interior wall and ceiling finishes.
How Does Class A Fire Retardant Coating Work?
Class A fire retardant coating is designed to significantly reduce the spread of fire and lessen its impact through a combination of mechanisms:
Intumescent Properties
A primary characteristic of Class A fire retardant coating is its ability to intumesce or expand when exposed to high temperatures. This intumescence occurs as the coating reacts to heat, swelling several times its original thickness. The resulting expanded layer forms a dense, insulative char that protects the material beneath from the flames. This char layer effectively delays the time it takes for the fire to reach the material underneath, providing crucial extra minutes for fire response and evacuation.
Flame Retardant Additives
The coating includes specific additives formulated to suppress the chemical reactions necessary for a fire to continue burning. These additives release compounds that either cool the fire or disrupt the free radicals driving the combustion process. By interfering with these chemical reactions, the coating helps to stall the spread of fire, providing additional protection to structures.
Thermal Insulation
Beyond its intumescent effect, Class A fire retardant coating also enhances thermal insulation. This feature creates a protective barrier that reduces the heat transfer rate to the protected surface. By keeping the underlying materials cooler, the coating prevents them from reaching the temperatures required for ignition, further safeguarding the structural integrity during a fire.
Smoke Reduction
Another significant advantage of Class A fire retardant coating is its ability to decrease the smoke and toxic gasses produced during a fire. This characteristic ensures occupants’ safety and evacuation efficiency in burning buildings. Lower smoke production means better visibility and less inhalation of harmful substances, which are often referred to as primary dangers in fires.
How Are Intumescent Coatings (Class-A) Tested According to ASTM E84 Standards?
Before these intumescent coatings get classified as Class A according to ASTM E84 standards, they must undergo comprehensive testing in specialized laboratories such as a QAI (Quality and Accreditation Institute) Laboratory, CAL FIRE-approved testing Laboratory, an IAS-recognized fire testing laboratory, and others.
During the test, the coated material is exposed to controlled fire conditions, and various parameters such as flame spread index and smoke development index are measured. Based on the test results, the coating is assigned a Class A rating if it meets the specified criteria for fire resistance.
Why Fire Retardant Coating Class A’s Working Principle Makes It a Preferred Choice?
When it comes to ensuring safety in various applications, opting for fire retardant coating, specifically Class A as per ASTM E84 standards, offers many benefits. Let’s discuss why choosing such coating is not only advantageous but also a wise investment across different scenarios.
Cost Efficiency
The claim of being the most economical fire retardant coating, saving approximately 35%, can’t be overstated. This aspect alone makes it a compelling choice for budget-conscious projects without compromising safety standards. With the rising costs of construction materials and stringent regulatory requirements, a cost-effective solution like this can positively impact your budget.
Comply ASTM Standards
These coatings not only meet but exceed ASTM E84 requirements. This includes the 30-minute extended test, which is crucial in determining the coatings’s ability to withstand fire over an extended period. By adhering to such rigorous standards, users can trust in the reliability and efficacy of the product, ensuring peace of mind in fire-prone environments.
High Performance
These coatings offer high performance in fire suppression. Their ability to meet ASTM E84 requirements at recommended application rates underscores their efficacy in containing and inhibiting the spread of flames. This is particularly crucial when rapid fire spread can lead to several consequences.
Ease of Application
The self-priming nature of the coating streamlines the application process, saving both time and resources. With a smooth architectural-grade finish and exceptional adhesion, the application becomes hassle-free. Users can achieve optimal results with minimal effort, whether by a brush, a roller, or a sprayer.
Environmental Considerations
In today’s eco-conscious world, the eco-friendliness of these coatings sets them apart. With low VOCs significantly below regulatory limits, these coatings offer a safer alternative with minimal chemical exposure. This benefits the environment and ensures the well-being of occupants in the coated spaces, making it a sustainable choice for the long term.
Versatility
The ability of these coatings to be applied to various combustible materials further enhances their utility. From wood substrates like OSB and plywood to dimensional lumber and wood paneling, the versatility of these coatings makes them suitable for a wide range of applications. Whether in residential, commercial, or industrial settings, these coatings offer a reliable solution to reduce fire risks effectively.
Conclusion
Fire retardant coating (Class A – ASTM E84) offers a complete solution to enhance fire resistance in building structures. It reduces fire spread and damage through intumescence, flame retardant additives, thermal insulation, and smoke reduction. Adhering to ASTM standards, it provides cost-efficient, high-performance, and environmentally friendly protection, making it a preferred choice for various applications.
Firefree Coatings’ Class A fire retardant coating is a renowned high-quality, water-based, non-toxic, thin-film intumescent flame-resistant coating. Our products are tested to meet ASTM E84 standards and set the industry standard for noncombustibility. Our coatings are recognized for their lower VOCs and offer superior fire protection, enhancing safety in diverse applications. Call us today!