Rockwool Flexi Slabs
Acoustic and thermal building slabs
Dual purpose acoustic and thermal mineral wool insulation with a patented Flexi® edge along one side.
Suitable for a wide range of applications, fitting all stud and joist centers with ease.
Will not slump, even if studs shrink.
Non-combustible – Euroclass A1.
Made from diabase rock, which is a renewable and plentiful natural resource.
Does not contain gases that have ozone depletion potential (ODP) or global warming potential (GWP).
Thicknesses and Availability:
This Rockwool Range includes the following readily available product thicknesses: 50mm, 60mm, 70mm, 90mm, 100mm, 140mm, and 180mm (some thicknesses may only be available in pallet quantities as they will need to be sourced from the manufacturer before being delivered to site).
The following thicknesses are manufactured to order and have minimum order requirements: 120mm (minimum order: 16 x pallets).
General information about Rockwool Flexi Slabs
Thermal and Acoustic flexi edge Building Slab
Rockwools versatile flexi edge building slab, Rockwool Flexi, is suitable for use in pitched roof rafters, framed external walls, internal partitions, intermediate floors, separating walls and floors, and timber suspended ground floors.
Durable non-combustable stone wool spun from volcanic rock, resin bonded into slabs
|Thermal Conductivity||0.038 W/m·K (insulant thickness > 140 mm)
0.035 W/m·K (insulant thickness 140 - 180 mm)
|Nominal Density||approx. 33 kg/m³|
|Fire Performance||Classification A1||BS EN 13501-1|
|Surface Spread of Flame||Non-combustable|
|Slab Width||0.4m and 0.6m|
Buy Rockwool Flexi Slabs
Limited stock of the most popular thicknesses are held at most of our depots. Where we need to bring stock in from the manufacturer, please allow up to 2 weeks for delivery
Please observe the 'Star Rating' indicators to assess availability.
Generally 1 or 2 days for delivery
Generally 1 to 5 days for delivery
Generally 5 to 10 days for delivery
Generally 5 to 15 days for delivery
Please call to check availability and approximate lead times
Product availability depends upon stock levels at closest depot and delivery logistics to geographic locations
Product Performance and Guides
Product Performance, Manufacturer Certification, Downloads, and Installation Guides
While we have provided Thermal Resistance values for all thicknesses on the Rockwool Flexi datasheet, some thicknesses may not be readily available.
Items highlighted in green are generally held in stock at our depots.
|Flexi (400mm) 50mm||50mm||1.32 m²K/W||33 kg/m³|
|Flexi (400mm) 100mm||100mm||2.63 m²K/W||33 kg/m³|
|Flexi (400mm) 140mm||140mm||4.00 m²K/W||33 kg/m³|
|Flexi (600mm) 50mm||50mm||1.32 m²K/W||33 kg/m³|
|Flexi (600mm) 60mm||60mm||1.58 m²K/W||33 kg/m³|
|Flexi (600mm) 70mm||70mm||1.84 m²K/W||33 kg/m³|
|Flexi (600mm) 90mm||90mm||2.37 m²K/W||33 kg/m³|
|Flexi (600mm) 100mm||100mm||2.63 m²K/W||33 kg/m³|
|Flexi (600mm) 120mm||120mm||3.16 m²K/W||33 kg/m³|
|Flexi (600mm) 140mm||140mm||4.00 m²K/W||33 kg/m³|
|Flexi (600mm) 180mm||180mm||5.14 m²K/W||33 kg/m³|
Standards & Approval
Rockwool Flexi is included within the following NBS clauses: p10:140, p10:210, p10:230, p10:240, p10:250, k10:115, k10:125, k10:145, k10:155, k10:165, k10:185, k10:420, k11:215, k11:225, k11:235, k11:245, k20:150, k20:160, m10:290, and m13:260.
Rockwool Flexi achieves a reaction to fire classification of A1, as defined in EN13501-1.