Nullifire FJ260 Cavity Barrier – Passive Fire Protection for External Wall Cavities

The Nullifire FJ260 Cavity Barrier is a high-performance passive fire protection solution engineered to maintain compartmentation and restrict the spread of fire and smoke through building cavities. Manufactured from robust rock mineral wool, this non-ventilated cavity barrier delivers reliable fire resistance for vertical and horizontal applications in external wall systems, junctions, and around openings such as windows and doors. Designed for ease of installation and long-term durability, FJ260 helps ensure building safety and compliance with modern fire safety standards.

Key Features & Benefits
🔥 Up to 120 minutes fire resistance — Successfully tested to EN 1366-4 with up to EI 120 classification for integrity and insulation in cavity applications.

📏 Wide cavity suitability — Effective in cavities up to 600 mm wide with minimal compression required during installation.

🧱 Non-ventilated, closed state design — Helps maintain fire compartment lines without relying on ventilation gaps.

🛠️ Versatile installation — Suitable for both vertical and horizontal applications at compartment floors, walls, and around openings.

⚙️ Easy to install — Requires only 5 mm compression during fitting and is compatible with a range of wall systems, including structural frame systems (SFS).

🔁 Low maintenance — Once installed, it requires no ongoing maintenance.

Usage & Purpose
The FJ260 Cavity Barrier is used to close and protect external wall cavities in buildings, helping to prevent the vertical and horizontal spread of fire and smoke within voids formed by wall assemblies and junctions. It is ideal for use:

Between compartment floors and party walls

Around window and door openings

In conjunction with structural framing systems

Within cavities up to 600 mm wide

By maintaining fire-resistance performance where it matters most, FJ260 enhances occupant safety and supports compliance with fire compartmentation requirements.

Packaging & Dimensions
Standard form: Rigid rock mineral wool slab

Typical slab dimensions: ~1000 mm (L) × 605 mm (W) × 100 mm (Thickness)

Installation requirement: Minimum 5 mm compression for proper fit

Custom sizing: Can be cut to size on site where necessary

Note: Packaging quantities and slab dimensions may vary by supplier or upon request — consult the latest technical datasheets for specifics.

Colours & Finish
Natural mineral wool colour: Light beige/yellowish tone

Finish: Unfaced (plain stone mineral wool)

Optional finishes or encapsulations (e.g., foil facing or integrated DPC) may be available upon special request, subject to minimum order quantities and lead times.

Certificates & Approvals
Fire resistance tested to: EN 1366-4 up to EI 120 performance rating.

Reaction to Fire classification: Euroclass A1 (non-combustible when unfaced).

Independently tested and certified for use in a wide range of external wall systems, including SFS with various board types.

For full certification documentation, performance data, and safety datasheets, refer to the official FJ260 technical literature provided by the manufacturer.

Product Data Sheet Links

FJ260 Performance Table (en-GB).pdf                        

Sealing tapes and membranes_GB_IE_1-0 (1).pdf - Safety Data Sheets 

FJ260 Safety Data Sheet (en-GB).pdf - Safety Data Sheets            

NF_FJ260_datasheet_Cavity Barrier_en-GB_v2.pdf - TDS  

Nullifire Cavity Barriers Leaflet (en-GB).pdf

UL – EU Certificate

The above information is based on current test data, health and safety information and application instructions supplied by our suppliers and manufacturers of the products. It is supplied for guidance and to the best of our knowledge is true and accurate. Customers should satisfy themselves to the suitability of the products in its intended use and no guarantee is given or implied as the conditions of actual use are beyond our control. If in doubt the customer should consult the designer of the project or the local building control. 

Fire Stopping Shop, disclaim any liability for loss, damage or other expense which may arise from the use of this information, data or products refereed to and reserve the right to amend or change any details without notice. This statement does not affect your statuary rights.