Rockwool Fire Barrier EN is a high-performance, wire-reinforced stone wool insulation designed to prevent the spread of fire and smoke through concealed spaces such as ceiling voids and above partition walls. Offering up to 120 minutes of fire resistance (EI 120), it is a key passive fire protection solution for both residential and commercial buildings.
Typical scenarios where Fire Barrier EN is required:
- Above plasterboard partitions in commercial buildings
- Within ceiling voids to compartmentalise fire spread
- At junctions between walls and soffits
- Around service penetrations (pipes, ducts, cable trays)
- In roof voids with timber trusses
If a building design includes concealed voids that could allow fire to spread unseen, a cavity fire barrier like this is typically required to meet Building Regulations.
View our full range of fire barrier products, or explore our wider insulation range, including loft insulation.
Key Features:
- Provides up to 2 hours (EI 120) fire resistance when installed correctly
- Non-combustible stone wool – Euroclass A1 fire rating
- Suitable for concrete soffits, timber trusses, and voids above partitions
- Tested with service penetrations and single-leaf timber door sets
- Faced with foil on one or both sides for durability and ease of handling
- Quick to install with minimal maintenance required
- Manufactured from natural stone with no ODP or GWP gases
Specifications:
- Product Size: 50mm (thickness) x 1000mm (width) x 3800mm (length)
- Coverage: 3.8m² per roll
- Density: Approx. 100 kg/m³
- Fire Rating: Up to EI 120 minutes (tested to BS EN 1364-1:2015)
- Facing: Single-sided black foil (also available with double foil)
Fire Barrier Applications:
- Concrete soffits and structural steel protection
- Timber truss systems (parallel and perpendicular)
- Voids above plasterboard partitions
- Around service penetrations and door heads to maintain fire integrity
Fire Barrier vs Cavity Barrier
| Product Type | Use Case |
|---|---|
| Fire Barrier EN | Large concealed voids (ceilings, roof spaces) |
| Cavity Barrier | Smaller cavities (walls and façades) |
Fire Barrier EN is designed for larger concealed voids, whereas cavity barriers are typically used within wall cavities.
Performance and Compliance
Rockwool Fire Barrier EN is classified to BS EN 13501-2, with performance derived from testing to BS EN 1364-1 and BS EN 1634-1. When installed as part of a tested system, it can achieve up to EI 120 fire resistance.
The product has been tested with both concrete and timber supporting constructions, including service penetrations and fire-resisting door sets, helping maintain compartmentation integrity. The wire-reinforced roll provides stability and is typically installed using proprietary angle supports and clamping plates.
In addition to fire performance, the stone wool core offers acoustic absorption, helping to reduce flanking sound transmission through ceiling voids and partitions.
From a sustainability perspective, the product contains no gases with ODP or GWP, is recyclable, and has no hazardous classification under EU/UK REACH. It also aligns with common NBS clauses for cavity barriers in partitions and suspended ceilings (K10/P10).
The full datasheet is available here.



