Building fire retardant coatings: provide a solid fire barrier for steel and wood structures

Below is an overview of how specially engineered fire-retardant coatings form a robust barrier around steel and wood structural elements, extending safe evacuation times and preserving structural integrity under fire exposure. These coatings—ranging from ultra-thin intumescent paints on steel to expanding, water-based systems on wood—are formulated to meet industry standards (e.g., ASTM E119/UL 263, ASTM E84, TB 117-2013), deliver aesthetic finishes, and support sustainable construction practices.

Fire Protection for Steel Structures

Structural steel elements (columns, beams, frames) must retain at least 50 % of their strength under fire conditions to prevent collapse during a standardized cellulosic fire test.
Intumescent coatings expand when heated, forming a char layer that insulates steel and delays temperature rise, allowing up to 4 hours of fire resistance at specified film thicknesses.
Typical applied thickness for thin-film intumescent coatings ranges from 0.8 mm to 13 mm (30–500 mils) depending on the required fire-resistance rating and steel section size.
Both solvent-based (e.g., FIRETEX® FX2007) and modern water-based thin-film products provide architectural finishes without adding significant bulk.
Closed-loop solvent recovery systems enable manufacturers to reclaim and reuse methyl acetate or other carrier solvents, reducing VOC emissions and enhancing environmental compliance.

Fire Protection for Wood Structures

Wooden beams, columns, and panels are inherently combustible and require coatings that swell at high temperatures to form a thick, insulating barrier.
Water-based, expanding intumescent paints (e.g., clear or white formulations) can upgrade existing timber surfaces to achieve 30–60 minutes of fire integrity per ASTM E84/UL 723 standards.
Decorative intumescent varnishes maintain the natural timber appearance while providing Class A flame spread ratings and UV resistance for both interior and exterior applications.
Single-coat systems designed for wood deliver up to 15 minutes of thermal barrier on spray-foam substrates, demonstrating versatility across combustible materials.

Types of Fire Retardant Coatings

Intumescent Coatings for Steel

– Thin-film intumescents are ideal for commercial and residential buildings, offering minimal DFT with high-rise performance up to 4 hours under UL 263/ASTM E119.
– Thick-film intumescents (500–1 300 µm) suit oil & gas and industrial settings where hydrocarbon fire exposure demands greater char expansion and protection.

Expanding Coatings for Wood

– Water-based intumescent paints like BAUMERK ANTI-FIRE WB form an insulating char layer up to 3 hours, safe for interior use due to low VOC content.
– Clear intumescent varnishes preserve wood aesthetics, enabling fire upgrades on doors, joists, and panelling without stripping existing finishes.

Selection Criteria and Application

– Performance Rating: Match coating type and thickness to required fire‐resistance period (e.g., 30 min, 60 min, up to 4 h) as per ASTM E119/UL 263 or local codes.
– Substrate Compatibility: Choose solvent-based or water-based formulations based on environmental controls, indoor air-quality needs, and application conditions.
– Aesthetic Requirements: Opt for formulations with clear or fine-texture finishes to maintain architectural appearance while delivering fire protection.
– Durability: Ensure coatings withstand cleaning, moisture, and UV exposure, retaining fire-resistant properties over decades.

Conclusion

By selecting appropriate fire-retardant coatings—intumescent for steel and expanding for wood—engineers and architects can create resilient, code-compliant structures that protect occupants and assets. Advances in water-based, low-VOC systems and closed-loop recovery further align these solutions with sustainable building practices, ensuring long-term performance and environmental responsibility.

Lior Lee

Email: lilin@hzruico.com