This item
ROCKWOOL Rocksafe Plus Rocksafe Plus · 135 mm · 600 × 1,200 mm · 80 kg/m³
- Thickness (mm)
- 135
- Density (kg/m³)
- 80
- Width (mm)
- 600
- Length (mm)
- 1200
ROCKWOOL Rocksafe Plus curtain-wall safing
Stone-wool slab for sealing the gap between a curtain wall and the floor slab edge, to stop fire spreading between floors and keep each fire compartment intact.
- Thickness
- 135 mm
- Density
- 80 kg/m³
- Reaction to fire
- Non-combustible BS 476 Part 4
Product details
Stone-wool safing for the gap between curtain wall and floor edge
- Thickness
- 135 mm
- Density
- 80 kg/m³
- Reaction to fire
- Non-combustible BS 476 Part 4
- Thermal conductivity (λ)
- 0.035 W/m·K at 20 °C · ASTM C518
What is it?
Rocksafe Plus is a ROCKWOOL stone-wool slab for curtain-wall fire protection. It seals openings in hidden areas such as the gap between the curtain wall and the floor edge, to prevent fire spread and keep each floor's fire compartment intact. 135 mm thick, 80 kg/m³, 600 × 1,200 mm.
What is it made of?
Stone wool (rock wool) · Slab
Which sizes are available?
Thickness 135 mm · 80 kg/m³ — Request a price
Limitations to know
The fire result belongs to the tested installation; install to the maker's details and check local-authority approvals as the maker advises.
Where does the data come from?
Rocksafe Plus data sheet 300 301-11/20 V4
Technical data from the manufacturer's documents ROCKWOOL · Checked 26 Sept 2026
Technical specifications
All values come from the manufacturer's documents, with conditions and test standards. Values the documents do not state are not shown.
| Property | Value | Conditions / standard | Source |
|---|---|---|---|
| Reaction to fire | Non-combustible | BS 476 Part 4 | Rocksafe Plus data sheet 300 301-11/20 V4, p. 2 |
| Thermal conductivity (λ) | 0.035 W/m·K | at 20 °C · ASTM C518 | Rocksafe Plus data sheet 300 301-11/20 V4, p. 2 |
| Density | 80 kg/m³ | — | Rocksafe Plus data sheet 300 301-11/20 V4, p. 2 |
| Melting point | ≥ 1,000 °C | DIN 4102-17 | Rocksafe Plus data sheet 300 301-11/20 V4, p. 2 |
| Water absorption (partial immersion) | < 0.5 kg/m² | EN 1609:97 | Rocksafe Plus data sheet 300 301-11/20 V4, p. 2 |
System-level values
Sound insulation ratings (STC / Rw) and fire-resistance ratings belong to the complete tested wall, ceiling or floor system — not to the insulation on its own.
ROCKWOOL reports a 2-hour result to BS 476 Part 20 for a tested installation: 135 mm slabs compressed by at least 15% of their width, fitted into openings in a concrete floor slab. This is not a property of the slab on its own.
Models and sizes available
| Model | Thickness (mm) | Density (kg/m³) | Width (mm) | Length (mm) |
|---|---|---|---|---|
| Rocksafe Plus | 135 | 80 | 600 | 1200 |
Pack quantities and prices — ask us on LINE
Applications
Highlights
- For the curtain-wall / floor-edge gap
- Non-combustible to BS 476 Part 4
- System tested to BS 476 Part 20
Related products
Alternatives
Fire protection · Stone wool
ROCKWOOL Conlit H110
- Thickness
- 25–100 mm
- Density
- 110 kg/m³
- Thermal conductivity (λ)
- 0.039 W/m·K
Helpful before you choose
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