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Buy Mineral Wool Building and Cavity Slabs, plus Fire Barrier System

Rockwool stone mineral wool slabs are commonly available from the majority of our depots for delivery within one or two working days. Rockwool slabs come in thickness's of - 25mm, 30mm 40mm, 50mm, 60mm, 75mm, and 100mm, in the following densities - Flexi = 33 kg/m³  | RWA45 = 45 kg/m³ | RW3 = 60 kg/m³ | RW5 = 100 kg/m³ | RW6 = 140 kg/m³.

Knauf Earthwool slabs are generally available in and around London. Outside of London supplies can be challenging, with minimum order quantities requirements a possibility. Available in the following thickness's thickness's, 25mm, 30mm 40mm, 50mm, 60mm, 75mm, and 100mm, and densities, RS33 = 33 kg/m³ | RS45 = 45 kg/m³ | RS60 = 60 kg/m³ | RS100 = 100 kg/m³ | RS140 = 140 kg/m³.

Building Slabs and Flexi Slabs

Rockwool Building Slab RW3 Fitted under pitched roof

Mineral wool slabs can be used in a wide range of thermal and acoustic insulation applications, in roofs, ceilings, loft conversions, walls and floors. The standard products are supplied un-faced, but they can be manufactured with a factory applied foil or tissue facing. Rockwool Full-Fill Cavity Insulation Slabs fitted to exterior wall

Rockwool insulation slabs are high quality resin bonded water repellent batts that can be used for thermal, acoustic and fire insulation. Rockwool slabs are used in applications where effective acoustic and thermal insulation is essential, such as in walls, partitions, floors and roofs, and can be fitted between timber and metal stud frames.

Earthwool slabs are similar to those manufactured by Rockwool, but with the added advantage of eco-friendly ECOSE technology which benefits from a natural, formaldehyde-free, binder made from rapidly renewable organic materials instead of petroleum-based chemicals. Earthwool (formerly Rocksilk) slabs, manufactured by Knauf, are unfaced, rock mineral wool batts, that can be used in a wide range of thermal and acoustic insulation applications. These slabs are available from us in densities from 33 kg/m³ to 140 kg/m³

Flexible Slabs are multi-purpose thermal and acoustic insulation slabs specifically designed for installation by friction fitting due to a flexible edge that compresses during fitting.


Rockwool Mineral Wool Building Slabs

Rockwool Stone Mineral Wool Building, Flexi and Cavity Slab. Also Fire Barrier System

These slabs are particularly suitable for acoustic infills in partitions and ceilings, providing a high level of control of both airborne and structure-borne sound. They are also suitable for acoustic absorption in the linings of buildings.

Mineral slabs of a density of 45 kg/m³ have now become the de-facto standard for normal domestic insulation purposes. Densities above this level are particularly good for use in sound studios and commercial and industrial areas where, for example, machine noise is prevalent.

Availability: These products, although popular, come on pallets of 24 rolls and commonly require a lead-time in excess of five working days.

Price List: Rockwool Building Slabs  - Unfaced Slabs - Thermal conductivity = 0.035W/mK

Fuller details of this product are available: Click Here.


1. Click items below for pricing structure. 2. Click Tick-Box to select one or more items. 3. Click Add to Cart Button.

Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RWA45 25mm, 16 x 0.6x1.2m = 11.52m² - start at £13.07
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RWA45 50mm, 9 x 0.6x1.2m = 6.48m² - start at £16.66
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RWA45 75mm, 6 x 0.6x1.2m = 4.32m² - start at £15.77
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RWA45 100mm, 4 x 0.6x1.2m = 2.88m² - start at £13.57
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RW3 30mm, 15 x 0.6x1.2m = 10.8m² - start at £26.83
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RW3 40mm, 10 x 0.6x1.2m = 7.2m² - start at £23.57
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RW3 50mm, 8 x 0.6x1.2m = 5.76m² - start at £22.96
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RW3 60mm, 6 x 0.6x1.2m = 4.32m² - start at £21.28
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RW3 75mm, 6 x 0.6x1.2m = 4.32m² - start at £25.81
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RW3 100mm, 4 x 0.6x1.2m = 2.88m² - start at £23.05
Rarely requested product sourced directly, possibly manufactured to order. Rockwool ProRox SL 950 50mm, 6 x 0.6x1.2m = 4.32m² - start at £22.91
Rarely requested product sourced directly, possibly manufactured to order. Rockwool ProRox SL 950 75mm, 4 x 0.6x1.2m = 2.88m² - start at £22.77
Rarely requested product sourced directly, possibly manufactured to order. Rockwool ProRox SL 950 100mm, 3 x 0.6x1.2m = 2.16m² - start at £22.82
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RW5 25mm, 8 x 0.6x1.2m = 5.76m² - start at £17.55
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RW5 30mm, 8 x 0.6x1.2m = 5.76m² - start at £21.09
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RW5 40mm, 6 x 0.6x1.2m = 4.32m² - start at £21.14
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RW5 50mm, 4 x 0.6x1.2m = 2.88m² - start at £17.14
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RW5 60mm, 4 x 0.6x1.2m = 2.88m² - start at £21.28
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RW5 75mm, 3 x 0.6x1.2m = 2.16m² - start at £19.27
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Building Slab RW5 100mm, 2 x 0.6x1.2m = 1.44m² - start at £17.07
Rarely requested product sourced directly, possibly manufactured to order. Rockwool ProRox SL 980 30mm, 6 x 0.6x1.2m = 4.32m² - start at £23.19
Rarely requested product sourced directly, possibly manufactured to order. Rockwool ProRox SL 980 50mm, 3 x 0.6x1.2m = 2.16m² - start at £19.32
Rarely requested product sourced directly, possibly manufactured to order. Rockwool ProRox SL 980 75mm, 2 x 0.6x1.2m = 1.44m² - start at £19.82
Rarely requested product sourced directly, possibly manufactured to order. Rockwool ProRox SL 980 100mm, 2 x 0.6x1.2m = 1.44m² - start at £25.65


Knauf Earthwool Building Slabs

Earthwool building, flexi and cavity slabs, plus loft, rafter and acoustic rolls

The standard products are supplied un-faced, but they can be manufactured with a factory applied foil or tissue facing, they are also available in a water repellent grade.

These slabs, branded 'RS' (short for Rocksilk, by which they were formerly known) are followed by the number that relates to their density per cubic metre. RS33 = 33 kg/m³ | RS45 = 45 kg/m³ | RS60 = 60 kg/m³ | RS80 = 80 kg/m³ | RS100 = 100 kg/m³ | RS140 = 140 kg/m³.

Availability: Although these products are popular, availability is sketchy, particularly outside of London. Please consider Rockwool products as an alternative.

Price List: Knauf Earthwool Building Slabs - Unfaced Slabs - Thermal conductivity = 0.035W/mK

Fuller details of this product are available: Click Here.


1. Click items below for pricing structure. 2. Click Tick-Box to select one or more items. 3. Click Add to Cart Button.

Our Prices are currently being revised please contact us for the latest prices

Our Prices are currently being revised please contact us for the latest prices

Our Prices are currently being revised please contact us for the latest prices

Our Prices are currently being revised please contact us for the latest prices

Pallet Quantities Only - Limited Availability

Our Prices are currently being revised please contact us for the latest prices



Rockwool Flexi Flexible Mineral Slabs

Rockwool Stone Mineral Wool Building, Flexi and Cavity Slab. Also Fire Barrier System

Rockwool Flexi is a multi-purpose, flexible (on one edge), non-combustible, mineral wool slab specifically designed for installation by friction fitting. They are typically used for the thermal and acoustic insulation of a wide variety of constructions such as stud partitions, either timber or metal, timber frame walls and suspended timber floors.

Uniquely, Rockwool Flexi is available in widths of 400mm as well as the standard 600mm.

Availability: These products are popular, and are commonly available at our depots.

Price List: Rockwool Flexible Slabs - Stone Mineral Wool - Unfaced Slabs - Thermal conductivity = 0.035W/mK

Fuller details of this product are available: Click Here.


1. Click items below for pricing structure. 2. Click Tick-Box to select one or more items. 3. Click Add to Cart Button.

Rarely requested product sourced directly, possibly manufactured to order. Rockwool Flexi 50mm, 12 x 0.4x1.2m = 5.76m² - start at £16.05
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Flexi 100mm, 6 x 0.4x1.2m = 2.88m² - start at £17.33
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Flexi 140mm, 4 x 0.4x1.2m = 1.92m² - start at £16.18
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Flexi 50mm, 12 x 0.6x1.2m = 8.64m² - start at £24.45
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Flexi 100mm, 6 x 0.6x1.2m = 4.32m² - start at £24.22
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Flexi 140mm, 4 x 0.6x1.2m = 2.88m² - start at £24.33

Knauf Flexible Slabs

Earthwool building, flexi and cavity slabs, plus loft, rafter and acoustic rolls

Earthwool Flexible Slab is also a multi-purpose, flexible (all four edges), non-combustible, rock mineral wool slab specifically designed for installation by friction fitting. They are typically used for the thermal and acoustic insulation of a wide variety of constructions such as timber and metal stud partitions, timber frame walls and suspended timber floors.

Availability: Although these products are popular, availability is sketchy, particularly outside of London. Please consider Rockwool products as an alternative.

Price List: Knauf Earthwool Flexi Slabs - Stone Mineral Wool - Unfaced Slabs - Thermal conductivity = 0.035W/mK

Fuller details of this product are available: Click Here.


1. Click items below for pricing structure. 2. Click Tick-Box to select one or more items. 3. Click Add to Cart Button.

Our Prices are currently being revised please contact us for the latest prices


Rockwool Cavity Batts

Rockwool Stone Mineral Wool Building, Flexi and Cavity Slab. Also Fire Barrier System

Rockwool cavity insulation is a rigid full-fill insulation solution for masonry cavity wall construction, suitable for use in new builds or extensions. Lightweight and easy to handle, the batts are simple to install and provide a close fit against brick and blockwork, adapting to imperfections in the cavity wall. They are are non-combustible and contain water repellent additives that prevent moisture transmission between the outer and inner leaf.

Availability: These products are popular, and are commonly available at all of our depots.

Price List: RockwoolFull Fill and Partial Fill Cavity Slabs - Mineral Stone Wool

Fuller details of this product are available: Click Here.


1. Click items below for pricing structure. 2. Click Tick-Box to select one or more items. 3. Click Add to Cart Button.

Rarely requested product sourced directly, possibly manufactured to order. Rockwool Cavity Insulation 50mm, 12 x 0.455x1.2m = 6.55m² - start at £19.74
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Cavity Insulation 75mm, 9 x 0.455x1.2m = 4.91m² - start at £19.63
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Cavity Insulation 80mm, 8 x 0.455x1.2m = 4.37m² - start at £21.86
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Cavity Insulation 100mm, 6 x 0.455x1.2m = 3.28m² - start at £16.94


Knauf Dritherm Cavity Slabs

Earthwool building, flexi and cavity slabs, plus loft, rafter and acoustic rolls

Earthwool DriTherm Cavity Slabs are semi-rigid or rigid slabs of non-combustible, water repellent, glass mineral wool. They are 455mm wide to suit standard vertical wall tie spacings, ensuring a closed joint with adjacent slabs. Earthwool DriTherm Cavity Slabs are for the thermal insulation of masonry cavity external walls and can be installed to fully fill the cavity. They are approved for use in buildings up to 12m high in any exposure zone and for use in multi-storey applications up to 25m in height.

Availability: Although these products are popular, availability is challenging, particularly outside of London. Please consider Rockwool products as an alternative.

Price List: Knauf Earthwool Dritherm Full Fill and Partial Fill Cavity Wall Insulation - Glass Mineral Wool Slabs

Fuller details of this product are available: Click Here.


1. Click items below for pricing structure. 2. Click Tick-Box to select one or more items. 3. Click Add to Cart Button.

Less popular product commonly available at selected depots. Knauf Earthwool® DriTherm Cavity Slab 32 Ultimate 75mm, 6 x 0.455x1.2m = 3.28m² - start at £18.28
Less popular product commonly available at selected depots. Knauf Earthwool® DriTherm Cavity Slab 32 Ultimate 85mm, 5 x 0.455x1.2m = 2.73m² - start at £16.81
Less popular product commonly available at selected depots. Knauf Earthwool® DriTherm Cavity Slab 32 Ultimate 100mm, 6 x 0.455x1.2m = 3.28m² - start at £22.43
Less popular product commonly available at selected depots. Knauf Earthwool® DriTherm Cavity Slab 37 Standard 50mm, 12 x 0.455x1.2m = 6.55m² - start at £14.15
Less popular product commonly available at selected depots. Knauf Earthwool® DriTherm Cavity Slab 37 Standard 65mm, 10 x 0.455x1.2m = 5.46m² - start at £14.57
Less popular product commonly available at selected depots. Knauf Earthwool® DriTherm Cavity Slab 37 Standard 75mm, 8 x 0.455x1.2m = 4.37m² - start at £12.98
Less popular product commonly available at selected depots. Knauf Earthwool® DriTherm Cavity Slab 37 Standard 85mm, 8 x 0.455x1.2m = 4.37m² - start at £13.69
Less popular product commonly available at selected depots. Knauf Earthwool® DriTherm Cavity Slab 37 Standard 100mm, 12 x 0.455x1.2m = 6.55m² - start at £20.94
Less popular product commonly available at selected depots. Knauf Earthwool® DriTherm Cavity Slab 37 Standard 125mm, 6 x 0.455x1.2m = 3.28m² - start at £14.60


Rockwool Fire Barrier System

Rockwool Stone Mineral Wool Building, Flexi and Cavity Slab. Also Fire Barrier System

Fire Barrier systems offer solutions to prevent fire and smoke spread within roof and ceiling voids. The vertically hung fire barriers are capable of achieving both integrity and insulation protection periods from 15 to 120 minutes of integrity and insulation. Rockwool’s essential insulation performance limits the heat transfer through the barriers, preventing ignition of combustible materials in adjacent areas. Rockwool's patented ‘Quick Fit’ support system offers a fast, cost effective installation method for Fire Barriers, for periods of up to 60 minutes, and focuses on ease of construction and installation, and has the added benefit of reducing the risks of installation errors.

Availability: These products are popular, and are available at many of our depots. However, we suggest allowing a 4 - 5 day lead-time.

Price List: Rockwool Fire Barrier System - Fire insulation with angle bracket and clamping plate system

Fuller details of this product are available: Click Here.


1. Click items below for pricing structure. 2. Click Tick-Box to select one or more items. 3. Click Add to Cart Button.

Rarely requested product sourced directly, possibly manufactured to order. Rockwool Easyfit Fire Barrier Angle, length = 3lm - start at £17.21
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Easyfit Fire Barrier Clamping Plate, length = 3lm - start at £9.63
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Fire Barrier - foil on both faces 50mm, 1x4m = 4m² - start at £75.86
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Plain Fire Barrier 50mm, 1x4m = 4m² - start at £32.39
Rarely requested product sourced directly, possibly manufactured to order. Rockwool Plain Fire Barrier 60mm, 1x3.5m = 3.5m² - start at £35.62


Product availability indicators

Price and Availability Advisory: Mineral Wool Slabs

Presently there are no availability restrictions, apart from manufacturing lead-times and minimum quantity order levels on certain product sizes. Observe the 'Star Rating' indicators to assess availability.

Excellent = Product Availability Excellent Good = Product Availability Good Fair = Product Availability Fair Poor =  Product Availability Poor Undetermined = Product Availability Undetermined
Availability relies on stock levels at closest depots and upon transport logistics to effect deliveries


Priced on Application:

Generally, either Rockwool or the Knauf Earthwool Mineral Slab should be available for fairly speedy delivery.

Estimates for large quantity orders can be priced on application. Please contact us to discuss such matters.

Contact us directly for further information: Telephone 0333 8000 828  - Email: Click Here:



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Use Products Brands Menu or Links below

Brand: Knauf Earthwool and Glass Mineral Wool Rolls

Brand: Rockwool Mineral Wool Slabs

Contact us

Insulation Online Limited

27 Massetts Road, Horley, Surrey, RH6 7DQ, UK

Telephone: 0333 8000 828

Facsimile: 0333 7000 797

Email: enquiries@insulation-online.com

Web site: www.insulation-online.com

insulation-online.com - we always deliver top quality products, competitive pricing and an efficient caring service