Rockwool Hardrock Multi-Fix Underlay Slab is designed to be used below Rockwool Hardrock Multi-Fix boards as a base layer to improve the overall sound and thermal insulation in flat roofing applications.
Made from stone mineral wool slab, it is non-combustible – ideal for roofing applications where fire resistance is a primary concern.
- 150mm thickness
- Suitable for use in flat roofing
- Non-combustible board compatible with a range of waterproofing systems
- Install under Rockwool Hardrock Multi-Fix
- Euroclass A2-s1, d0 resistance to fire
What Size is Rockwool Hardrock Underlay Slab?
Rockwool Hardrock Recovery Board measures 1000mm wide by 1200mm long (1.2m²) and is 150mm thick.




