Fire-resistant coatings play a crucial role in protecting buildings from the rapid spread of flames. Whether applied indoors or outdoors, these specialized paints and coatings delay fire damage, giving occupants more time to evacuate during wildfires and reducing structural harm.
However, interior and exterior fire-resistant coatings have different purposes. Understanding the differences between these coatings ensures you choose the right product for maximum safety and longevity. In this blog, we will discuss the same.
The Difference Between Interior and Exterior Fire-Resistant Coatings
Choosing the correct fire-resistant coating depends on environmental exposure, substrate material, and its use. Let’s discuss it in detail!
Durability & Environmental Resistance
Exterior fire-resistant coatings are specifically made to withstand the intense conditions brought on by wildfires. These products contain UV-resistant polymers and additives that prevent degradation from sunlight, rain, and extreme temperatures during wildfire events. On the other hand, fire-retardant interior paint is made for stable, climate-controlled spaces. While it effectively slows flame spread on walls and ceilings, it lacks the weatherproofing needed for outdoor use.
Corrosion Protection for Structural Strength
When applied to steel or metal surfaces, exterior fire-retardant paint often includes anti-corrosion properties. This helps prevent rust formation, which can weaken structural components over time. During a wildfire, rust-related damage can lead to serious financial losses and pose a threat to your safety and that of your loved ones. In contrast, heat-resistant paint for interior walls prioritizes fire protection without necessarily offering rust prevention, as indoor environments are generally less exposed to moisture and corrosion.
Substrate-Specific Applications
Exterior fire-resistant coatings are commonly used on exposed structural elements such as steel beams, cladding, and outdoor framing areas that must retain their strength under wildfire conditions. Their primary function is to preserve load-bearing capacity when flames threaten the structure. Interior fire-retardant house paint, on the other hand, is applied to drywall, wood, and framing within homes and buildings to meet fire safety codes and protect occupants in places like schools, hospitals, and offices.
Application & Curing Process
Applying exterior fire-resistant coatings for wildfire defense often involves multiple layers and longer curing times. Some products may also require a protective topcoat to enhance longevity. Interior coatings are generally easier to apply, with quicker drying times and compatibility with standard spray equipment, ideal for rapid deployment in residential and commercial interiors.
Fire-Resistant Coating Products and Their Applications
There are different types of fire-resistant coating products available, tailored for the level of fire protection required. This includes:
Firefree 88®
Firefree 88® is a high-performance fire-resistant coating specifically designed for interior applications. It requires careful surface preparation, including priming for metal and concrete substrates, and must be applied under controlled temperature and humidity conditions. Application is best done with an airless sprayer, and thickness must be monitored to meet safety standards.
Firefree Class A
Firefree Class A is a fire-retardant paint ideal for interior wood surfaces, meeting all ASTM E84 standards, including the 30-minute extended test. It transforms combustible materials like plywood, OSB, and Douglas fir into noncombustible surfaces. Suitable for residential, commercial, and industrial projects, it offers a simple & effective way to enhance fire safety in interior environments.
Firefree Exterior System
The Firefree Exterior System is made for outdoor use, especially in wildfire-prone areas. It has passed rigorous ASTM D2898 weatherization tests, proving its resistance to water and UV exposure. This durable, easy-to-apply coating provides passive fire protection for exterior wood surfaces and often requires no primer.
Conclusion
Fire-resistant coatings are essential for safeguarding buildings, but interior and exterior variants serve distinct purposes. Exterior coatings withstand harsh weather and prevent corrosion, while interior options focus on flame retardation in controlled environments. Choosing the right product, based on substrate, durability, and application, ensures optimal fire protection.
Firefree Coatings, Inc., provides interior and exterior fire-resistant coatings, ensuring buildings meet wildfire safety standards. Our coatings are rigorously tested with ASTM standards for flame spread and smoke development. Contact Us Today!