Rockwool Flexi Stone Wool Insulation Slab 1200x600mm
Flexible Stone Wool Insulation for Walls, Floors and Roofs
Rockwool Flexi is a multi-purpose stone wool insulation slab designed for both acoustic and thermal performance. It features a flexible edge that helps the slab friction-fit tightly between timber or metal studs, joists and rafters, reducing gaps during installation.
This makes it a practical choice for partition walls, floors, ceilings, roofs, timber frames and refurbishment projects where a close-fitting mineral wool insulation is required.
Rockwool Flexi is made from non-combustible stone wool and provides excellent fire, acoustic and thermal performance. It helps reduce airborne sound transfer between rooms while also improving heat retention within the building fabric.
The flexible edge makes installation easier, especially where stud or joist spacing is not perfectly consistent. Once fitted, the slab holds itself in position, helping maintain a continuous insulation layer without unnecessary cutting or waste.
Key features
- Flexible edge for a tight friction fit between studs, joists and rafters
- Helps reduce airborne sound transfer through walls, floors and ceilings
- Provides strong thermal insulation performance
- Made from non-combustible stone wool
- Suitable for timber and metal frame constructions
- Easy to cut and install around services
- Helps reduce gaps that can weaken acoustic and thermal performance
- Suitable for residential and commercial projects
Applications
Rockwool Flexi can be used in:
- Internal partition walls
- Timber and metal stud walls
- Separating floors
- Suspended timber floors
- Ceilings
- Pitched roofs
- Timber frame construction
- Garden rooms, studios and home offices
- General acoustic and thermal insulation upgrades
Technical specifications
| Specification | 100mm Variant | 140mm Variant |
|---|---|---|
| Product | Rockwool Flexi | Rockwool Flexi |
| Thickness | 100mm | 140mm |
| Slab size | 1200mm x 600mm | 1200mm x 600mm |
| Slabs per pack | 6 | 4 |
| Coverage per pack | 4.32m² | 2.88m² |
| Material | Stone wool | Stone wool |
| Fire rating | Euroclass A1 non-combustible | Euroclass A1 non-combustible |
| Thermal conductivity | 0.038 W/mK | typically 0.035 W/mK |
| Main use | Acoustic and thermal insulation | Acoustic and thermal insulation |
Installation notes
Install Rockwool Flexi between timber or metal framing with the flexible edge compressed slightly against the frame. The slab should fit snugly with no visible gaps around the edges.
Cut with a suitable insulation knife where required. Avoid leaving voids, as gaps can reduce both sound insulation and thermal performance.
For soundproofing projects, Rockwool Flexi should be used as part of a complete system with suitable acoustic plasterboard, isolation products, sealant and careful control of flanking noise.
FAQ
What is Rockwool Flexi used for?
Rockwool Flexi is used for acoustic and thermal insulation in walls, floors, ceilings and roofs. It is suitable for timber and metal frame construction.
What makes Rockwool Flexi different from standard slabs?
Rockwool Flexi has a flexible edge that helps it grip between studs, joists or rafters. This helps reduce gaps and makes installation easier.
Is Rockwool Flexi good for soundproofing?
Yes. Rockwool Flexi helps absorb airborne sound inside wall, floor and ceiling cavities. For stronger soundproofing, it should be used with suitable acoustic boards and acoustic sealing.
Is Rockwool Flexi fire resistant?
Yes. Rockwool Flexi is a non-combustible stone wool insulation product with a Euroclass A1 fire rating.
How many square metres are in a 100mm pack?
The 100mm pack covers 4.32m².
How many square metres are in a 140mm pack?
The 140mm pack covers 2.88m².
