In passive fire protection, coating structural steel to maintain its integrity during a fire is a critical requirement. Two of the most commonly used solutions are vermiculite spray coatings and intumescent paints. While both are designed to slow down the temperature rise of steel elements and prevent premature structural failure, they differ significantly in terms of application, performance, appearance and cost.
Vermiculite coatings consist of lightweight mineral aggregates in a cementitious slurry and are sprayed on in relatively thick layers. They offer excellent thermal insulation and are typically used in commercial or industrial environments where appearance is not a priority—such as basements, carparks, plant rooms and mechanical risers. These systems are cost-effective and suitable for covering large areas quickly. Their disadvantages include a rough finish, low impact resistance and vulnerability to moisture if not sealed or protected.
Intumescent coatings, by contrast, are reactive paints that expand when exposed to heat, forming a protective char that insulates the steel. Applied in thin layers (much like conventional paint), they can expand up to 50 times their original thickness when activated. This makes them ideal for architectural steelwork that must remain visible while still achieving fire protection. Common applications include commercial lobbies, atria, museums and exposed steelwork in residential towers.
Ceasefire PFP offers both systems to suit different project needs. For vermiculite installations we use Cafco®300, and for intumescent applications we apply Cafco® SPRAYFILM WB3. Both are installed to meet the required Fire Resistance Level (FRL), typically between 60 and 120 minutes, depending on steel size and exposure.
Selection should be based not only on cost and aesthetics, but also on site and installation conditions. Vermiculite requires careful substrate preparation and protection from moisture during curing. Intumescent paints are more sensitive to environmental conditions but deliver a smoother finish, lower overall thickness and generally faster installation times, especially in fit-out stages.
Ceasefire begins each project with a detailed assessment of the steel design, building use and architectural requirements. Our technicians also conduct adhesion and compatibility testing before application. Many clients are surprised to learn that although intumescent coatings have a higher upfront cost, they can often deliver lifecycle savings through reduced dead load, easier installation and increased asset value.
Maintenance is another important factor. Vermiculite can chip or crack upon impact and may require patching. Intumescent coatings are more durable, but may need localised recoating in high-traffic areas. Ceasefire provides maintenance inspections in accordance with AS 1851 to ensure ongoing compliance.
Both systems are highly effective when applied correctly. The choice ultimately depends on finding the right balance between performance, cost and aesthetics. Ceasefire PFP supports this decision-making process by providing side-by-side comparisons, material samples and lifecycle cost assessments.
Choosing the right fire-resistant coating is never one-size-fits-all. Engaging with specialists early ensures that code compliance is achieved — while also enhancing the value and safety of the project.
