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Table of Contents
What is Intumescent Paint?
Intumescent paint are fire resistant paints that passively protects your building’s most critical infrastructure in the event of a fire. Intumescent coatings form a protective char around your asset that prevents fire damage when exposed to extreme heats.
Related: Learn more about intumescent paints for wood and intumescent paints for steel.
Recommended Intumescent Paint Products
FlameOFF Fire Barrier Paint
FlameOFF Coatings (as the name implies) specializes in intumescent paints and sprays, and they have knowledgeable staff that can answer all your questions.
Best Intumescent Paint
Learn more about FlameOFF Fire Barrier Paint here.
Key features include:
- E84 compliant: Class A flame spread (tested and certified by a 3rd party lab)
- ASTM E119 compliant: 1 and 2-hour fire rated for long-lasting protection
- GREENGUARD Gold Certified: low VOC emissions for healthier indoor air quality
- Compatible with steel, wood, gypsum, sheetrock, metal, and more
- Gold Supplier Member of National Fireproofing Contractors Association
FlameOFF Fire Barrier Paint data sheets
Product and safety data sheets provide additional information for facility managers, coating professionals, and engineers. Take a look at the data below to see how it applies to your project.
- Safety data sheet
- Product brochure
- Data sheet for gypsum and wood
- Data sheet for structural steel
- UL GREENGUARD Gold Certification
Sherwin Williams Firetex Products
Sherwin Williams offers several different types of intumescent coatings including:
Firetex FX9502: A 100% solids intumescent epoxy that’s ASTM E119, UL 263, and UL 2431 certified.
- Can be used in the field and shops
- Reduces total cost by requiring fewer coats and a low dry film thickness requirement
- Chemical and corrosion resistant
Find the full Firetex FX9502 sell sheet here.
Firetex FX7002: A solvent-based, thin-film intumescent acrylic paint that’s UL 263 and UL S1011 certified.
- Best for on-site application
- Provides up to two hours of fire protection
- Impact resistant and low VOC
Find the full Firetex FX7002 sell sheet here.
Firetex FX6010: A multi-component, fast-drying intumescent coating that is ASTM E119, ASTM E84, UL 263, ULC S101, and UL CDXA certified.
- Suitable for field and shop applications
- Durable and weather resistant
- LEED v4 and v4.1 certified
Find the full Firetex FX6010 sell sheet here.
Firetex FX6002: A multi-component, ultra-fast drying intumescent coating that offers up to three hours of fire protection.
- ASTM E119, UL 263, UL CDYD, and ASTM E84 certified
- Can be exposed to weather after four hours of dry time
- Ultra-fast drying
Find the full Firetex FX6002 data sheet here.
Firetex FX5090: A water-based, thin-film intumescent paint that’s UL 263 certified.
- Provides up to two hours of fire protection
- Extremely smooth finish
- Can dry in as little as 90 minutes
Find the full Firetex FX5090 data sheet here.
Firetext FX5120: A water-based, thin-film intumescent paint that’s UL 263 certified and designed for several different types of steel beams and columns.
- High wet film properties
- Aesthetic finish with no fibers
- UL D981, UL N636, UL Y623, and UL624 approved
Find the full Firetex FX5120 data sheet here.
Sherwin Williams is a good manufacturer to consider if your project requires a variety of fireproofing coatings.
How to Choose an Intumescent Paint Supplier
There are several things you need to consider when selecting an intumescent paint supplier including fireproofing and environmental compliance, material adhesion, expertise, and membership in reputable organizations.
Fireproofing compliance: Are the intumescent formulas ASTM and UL certified? ASTM E119 (UL 263) and E84 (UL 723) are the most common standards for building materials.
Environmental compliance: Are the products you’re purchasing environmentally friendly and EPA compliant? Look for low VOC, high solids, and water-based coatings if your facility needs to meet EPA standards.
Material adhesion: Are the coatings designed specifically for the type of materials you’ll be painting (e.g. steel, wood, drywall, OSB, sheetrock, metal, etc.)?
Expertise: Is your supplier knowledgeable in ASTM, NFPA, and UL codes and standards? You’ll want to order from a company with many years of experience in the fireproofing space with sales reps and engineers on standby.
Membership in organizations: Is your paint supplier a member of fireproof organizations like the National Fireproofing Contractors Association (NFCA)? Membership in organizations like the NFCA ensure that your supplier’s team is investing in continued education around intumescent paint and other fireproofing technologies. The NFCA in particular requires all members to have at least two years and 20 jobs in the passive fireproofing business.
Intumescent Paint vs. Cementitious Paint
Intumescent coatings have become the de facto tool for passive fire protection, but there are two other types of coatings worth considering. The other categories in this field are dense concrete and lightweight cementitious fireproofing. Keep reading to understand the difference between intumescent and cementitious paint.
Lightweight cementitious coatings are cement-based products used to fireproof structures. Like intumescent paint, these coatings can stand up to very hot temperatures. As their name implies, they are much lighter than dense concrete.
That said, cementitious coatings have some notable drawbacks. One major problem – space between the substrate and the coating will develop over time. That space can become filled with moisture, encouraging corrosion. Cracking is a major issue with cementitious coatings, which is why proper surface preparation is so important.
| Cementitious Coatings | Intumescent Paints |
| More cost effective | More expensive |
| Not intended for visible areas of a building | Aesthetically pleasing |
| Coating can crack | Smoother finish |
| Heavy concrete | Lightweight formulation |
Because of these issues, cementitious coatings have lost popularity over time. Instead, intumescent fireproofing has become the go-to option for fire retardant paint today.
How Much Does Intumescent Paint Cost?
There’s both a short answer and a long answer to this question, but we’ll start with the long answer. Intumescent paint costs for your project can vary based on many factors. These factors include:
- Coating thickness
- Adhesion
- Required surface preparation
- Environmental resistance
- Expansion ratio (that is, how much a coating expands when exposed to high temperatures)
- VOC levels
With all that in mind, you can expect to pay anywhere from $4 to $12 per square foot of intumescent paint. The exact amount you’ll pay will depend on the factors listed above, among others.
Intumescent Paint Fire Ratings
There are lots of fire ratings out there, but which intumescent paint fire rating should you focus on? There are several standards to consider when purchasing a fireproofing coating, including:
- ASTM E84 / UL 723
- ASTM E119 / UL 263
- ANSI / UL 2431
ASTM E84
One important intumescent paint fire rating is American Society for Testing and Materials (ASTM) Test Method E-84, or “ASTM E84” for short. This rating focuses on a material’s flame-spread and smoke development.
In ASTM E84 tests, a 20″ x 25 ft. material sample is installed on a test chamber’s ceiling. Testers then apply a gas flame to one end of the sample. The results of this test determine the material’s flame spread rating (FSR) on a scale of 0-200, where the higher a flame spread number, the more flammable a material is. For reference, inorganic reinforced cement board has a rating of zero on this scale, while red oak has a rating of 100.
From there, materials fall into three classes:
- Class A materials have FSRs of 0-25
- Class B materials have FSRs of 26-75
- Class C materials have FSRs of 76-200
UL 723
UL 723 standards also measure flame spread and smoke development. These standards also involved similar test where a Steiner Tunnel is used to measure how much flame and smoke spread during a controlled burn. In fact, UL 723 and ASTM E84 are often used interchangeably.
ASTM E119
While ASTM E84 deals with flame-spread, ASTM E119 is all about how long a material can deal with fire. For intumescent paint, “2 hour rating” and phrases like it may refer to this test.
For ASTM E119 testing, a material sample is exposed to a temperature-controlled fire. This test measures the reliability of structural elements like:
- Bearing walls
- Partitions
- Columns
- Floors
- Roofs
- Beams
- Protective membranes
UL 263
UL 263 also tests the fire resistance of building construction and materials, and it applies to components such as walls, partitions, floors, roofs, beams, and columns. In fact, UL 263 standards are often used interchangeably with ASTM E119.
UL 263 ratings measure the number of hours a component can withstand continued exposure to fire, and the methodology is almost identical as ASTM E119 testing.
The key difference to consider is that some jurisdictions and or project stakeholders might not accept UL or ASTM standards. Be sure to consider the municipalities where your project is before purchasing an intumescent coating.
ANSI / UL 2431
ANSI / UL 2431 evaluates how durable a fire resistant material is when exposed to extreme environmental and weather. For example, UL 2431 measures a coatings effectiveness to extreme heat, cold, or exposure to water and corrosive environments.
UL 2431 is specifically the Standard for Durability of Fire-Resistive Coatings and Materials, so it’s important to consider when you’re asset is exposed to the elements.
Related articles: Best Fire Resistant & Fire Retardant Paints
Frequently Asked Questions
Intumescent paints are required when materials in your building (e.g. walls, structural steel, ceilings, etc.) need to meet ASTM E-119 standards.
Intumescent paint costs $4 to $12 per square foot. It’s relatively expensive compared to cheaper options like cementitious coatings.
Intumescent paint is typically applied with a paint sprayer, but it can also be applied with a paint brush or roller depending on the manufacturer’s specifications.
Most intumescent paints require a primer unless the manufacturer indicates it is a 2-in-1 solution with a primer and top coat. Check your coating’s technical specs!
Yes, most intumescent paints can be applied with a brush, roller, or paint sprayer.
The key to a smooth finish actually starts with surface preparation. Make sure to clean the area of dust, debris, and rust with a material blaster or pressure washer before applying your intumescent paint.
Intumescent paints will protect your asset during a fire between 30 minutes up to 4 hours, depending on the material and coating specification.
Intumescent paints are more aesthetically pleasing and more versatile than cementitious coatings.
It usually takes between 2 – 8 hours for an intumescent paint to fully dry, but this will vary by application, coating thickness, and jobsite conditions.
Yes. Intumescent paints are designed to improve ASTM E-119 fire ratings to meet ICS building code compliance.