FireMastic-300™
BOSS FireMastic-300™ is a high-performance flexible fire and acoustic acrylic sealant designed to seal joints, linear gaps and service penetrations in fire-rated walls, floors & ceilings. Tested to a market leading 5 hours or FRL -/300/300. It reinstates the integrity and insulation performance of fire-rated construction by preventing the passage of fire, smoke and hot gases through gaps and penetrations. Suitable for use around electrical and metallic plumbing services, FireMastic-300™ is an adaptable sealing solution ideal for both new construction and retrofit applications, offering strong adhesion and compatibility with a wide range of common substrates.
The sealant provides excellent tooling characteristics, good workability and superior acoustic performance, making it suitable for interior installations where movement or vibration is expected. FireMastic-300™ is low-VOC, water-based, paintable once cured, and is engineered for use across commercial, residential, industrial and infrastructure projects. Safe to apply using standard caulking equipment, it forms a durable joint seal that maintains long-term stability and compliance.
Applications
- Sealing joints, linear gaps and service penetrations in fire-rated walls & floors
- Electrical services including power, comms & data cables
- Plumbing penetrations around steel, copper & iron pipes
- Linear gap seals up to 50mm wide
- Steel sprinkler pipes without thermal blankets
- Apartment entry services, refurbishment and retrofits
- Commercial, industrial, infrastructure and residential projects
Key Benefits
- Maintains fire and acoustic performance
- Flexible movement capability
- Low VOC, water-based and paintable
- Adheres to most building materials without primer
- Cartridges made with recycled materials
- Provides excellent finish & tooling properties
- Suitable for multiple substrates, including:
- fire rated plasterboard
- Concrete & masonry
- Speedpanel & Korok
- AFS & Dincel
- AAC & Hebel
- Timber Applications
- Concrete floor slabs
- Plasterboard ceilings
Testing
FireMastic-300™ is designed to reinstate the fire resistance performance of fire-rated building elements by sealing penetrations and joints, and delivers fire, smoke, hot gas and acoustic containment performance in accordance with national construction code requirements. FireMastic-300™ is tested and assessed to AS1530.4:2014 and AS4072.1-2005.
Final tested FRL ratings, substrate compatibility and installation configurations should be confirmed against the FireMastic-300™ test and assessment documentation located via the BOSS Fire System Matrix.
