Where to buy insulation by thickness?

You can buy insulation by thickness from Insulation Wholesale. We stock multiple materials across a full depth range, so you can choose the material that best fits your construction build-up, without compromising. Our team helps match insulation thickness to your application, whether for floors, walls, roofs, or specialist applications. We supply UK stock and support both trade and DIY customers with clear advice and reliable delivery.

What insulation thickness is best?

There is no single “best” insulation thickness. The right choice depends on the space available, the target U‑value, and the material used. A thinner high‑performance foam can outperform a thicker fibrous product, while deeper mineral wool can give better sound control and fire resistance. Choose the thickest insulation that fits without compression while complying with UK Building Regulations.

Can different materials be mixed at the same thickness?

Yes, you may combine materials - as long as they are compatible and correctly detailed. You can combine a rigid board layer with mineral wool of the same depth to improve thermal control and sound absorption, for example. The key is to maintain continuity with no air gaps. Do a full vapour control and condensation risk assessment before combining materials.

Insulation By Thickness At Wholesale Prices

150mm Knauf DriTherm 37 Cavity Wall Insulation Slab 455mm x 1200mm 4.37m2 Pack

150mm Knauf DriTherm 37 Cavity Wall Insulation Slab 455mm x 1200mm 4.37m2 Pack

150mm DriTherm Cavity Slab 37 is a water-repellent Glass Mineral Wool slab, designed for use in external full-fill masonry cavity walls, that offers excellent thermal performance. It is non-combustible with the best possible Euroclass A1 reaction to fire classification

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150mm Rockwool Rainscreen Duo Slab 1200mm x 600mm 34.56m2 Pallet

150mm Rainscreen Duo Slab is dual-density insulation specifically developed for use within ventilated cladding systems, as well as sealed systems such as curtain walling. Once installed, the robust outer surface of the slabs, in combination with a factory applied water-repelling agent, acts to resist rain ingress during construction.

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180mm Rockwool Flexi Slab Acoustic Insulation 1200mm x 600mm 25.92m2 Pallet

180mm Rockwool Flexi has been designed as a multi-use, dual-purpose acoustic and thermal mineral wool insulation with a unique flexible edge along one side. It is suitable for use all over the home, in pitched roof rafters, framed external walls, internal partitions, intermediate floors, separating walls and floors, and timber suspended ground floors.

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180mm Rockwool Rainscreen Duo Slab 1200mm x 600mm 25.92m2 Pallet

180mm Rainscreen Du Slab is dual-density insulation specifically developed for use within ventilated cladding systems, as well as sealed systems such as curtain walling. Once installed, the robust outer surface of the slabs, in combination with a factory applied water-repelling agent, acts to resist rain ingress during construction.

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25mm Knauf Rocksilk RS45 Building Insulation Slab 1200mm x 600mm 14.4m2 Pack

25mm Knauf Insulation Rocksilk RS45 is a Rock Mineral Wool slab, designed for use in multiple thermal and acoustic applications. It is non-combustible with the best possible Euroclass A1 reaction to fire classification.

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25mm Rockwool RW3 Acoustic Insulation Slab 1200mm x 600mm 138.24m2 Pallet

25mm Rockwool RW3 Slabs can be applied to an array of general building applications for acoustic, thermal and fire protection of partition walls, ceilings, floors and roofs.

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25mm Rockwool RW5 Acoustic Insulation Slab 1200mm x 600mm 138.24m2 Pallet

25mm Rockwool RW5 Slabs can be applied to an array of general building applications for acoustic, thermal and fire protection of partition walls, ceilings, floors and roofs.

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25mm Rockwool RWA45 Acoustic Insulation Slab 1200 x 600mm 138.24m2 Pallet

25mm Rockwool RWA45 has been developed for thermal, acoustic and fire performance in a range of construction types. It is suitable for applications on partition walls, ceilings, floors and roofs.

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30mm Rockwool RW3 Acoustic Insulation Slab 1200mm x 600mm 129.60m2 Pallet

30mm Rockwool RW3 Slabs can be applied to an array of general building applications for acoustic, thermal and fire protection of partition walls, ceilings, floors and roofs.

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30mm Rockwool RW5 Acoustic Insulation Slab 1200mm x 600mm 115.20m2 Pallet

30mm Rockwool RW5 Slabs can be applied to an array of general building applications for acoustic, thermal and fire protection of partition walls, ceilings, floors and roofs.

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30mm Rockwool RWA45 Acoustic Insulation Slab 1200 x 600mm 138.24m2 Pallet

30mm Rockwool RWA45 has been developed for thermal, acoustic and fire performance in a range of construction types. It is suitable for applications on partition walls, ceilings, floors and roofs.

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40mm Rockwool RW3 Acoustic Insulation Slab 1200mm x 600mm 86.40m2 Pallet

40mm Rockwool RW3 Slabs can be applied to an array of general building applications for acoustic, thermal and fire protection of partition walls, ceilings, floors and roofs.

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40mm Rockwool RWA45 Acoustic Insulation Slab 1200 x 600mm 138.24m2 Pallet

40mm Rockwool RWA45 has been developed for thermal, acoustic and fire performance in a range of construction types. It is suitable for applications on partition walls, ceilings, floors and roofs.

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50mm Knauf Rocksilk RS45 Building Insulation Slab 1200mm x 600mm 7.2m2 Pack

50mm Knauf Insulation Rocksilk RS45 is a Rock Mineral Wool slab, designed for use in multiple thermal and acoustic applications. It is non-combustible with the best possible Euroclass A1 reaction to fire classification.

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50mm Rockwool Flexi Slab Acoustic Insulation 1200mm x 600mm 8.64m2 Pack

50mm Rockwool Flexi has been designed as a multi-use, dual-purpose acoustic and thermal mineral wool insulation with a unique flexible edge along one side. It is suitable for use all over the home, in pitched roof rafters, framed external walls, internal partitions, intermediate floors, separating walls and floors, and timber suspended ground floors.

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50mm Rockwool Rainscreen Duo Slab 1200mm x 600mm 69.12m2 Pallet

50mm Rainscreen Duo Slab is dual-density insulation specifically developed for use within ventilated cladding systems, as well as sealed systems such as curtain walling. Once installed, the robust outer surface of the slabs, in combination with a factory applied water-repelling agent, acts to resist rain ingress during construction.

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50mm Rockwool RW3 Acoustic Insulation Slab 1200mm x 600mm 69.12m2 Pallet

50mm Rockwool RW3 Slabs can be applied to an array of general building applications for acoustic, thermal and fire protection of partition walls, ceilings, floors and roofs.

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50mm Rockwool RW4 Acoustic Insulation Slab 1200mm x 600mm 69.12 m2 Pallet

50mm Rockwool RW4 Slabs can be applied to an array of general building applications for acoustic, thermal and fire protection of partition walls, ceilings, floors and roofs.

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50mm Rockwool RW5 Acoustic Insulation Slab 1200mm x 600mm 69.12m2 Pallet

50mm Rockwool RW5 Slabs can be applied to an array of general building applications for acoustic, thermal and fire protection of partition walls, ceilings, floors and roofs.

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60mm Rockwool Flexi Slab Acoustic Insulation 1200mm x 600mm 103.68m2 Pallet

60mm Rockwool Flexi has been designed as a multi-use, dual-purpose acoustic and thermal mineral wool insulation with a unique flexible edge along one side. It is suitable for use all over the home, in pitched roof rafters, framed external walls, internal partitions, intermediate floors, separating walls and floors, and timber suspended ground floors.

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60mm Rockwool Rainscreen Duo Slab 1200mm x 600mm 51.84m2 Pallet

60mm Rainscreen Duo Slab is dual-density insulation specifically developed for use within ventilated cladding systems, as well as sealed systems such as curtain walling. Once installed, the robust outer surface of the slabs, in combination with a factory applied water-repelling agent, acts to resist rain ingress during construction.

POA Get a quote

60mm Rockwool RW3 Acoustic Insulation Slab 1200mm x 600mm 51.84m2 Pallet

60mm Rockwool RW3 Slabs can be applied to an array of general building applications for acoustic, thermal and fire protection of partition walls, ceilings, floors and roofs.

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60mm Rockwool RWA45 Acoustic Insulation Slab 1200 x 600mm 92.16m2 Pallet

60mm Rockwool RWA45 has been developed for thermal, acoustic and fire performance in a range of construction types. It is suitable for applications on partition walls, ceilings, floors and roofs.

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70mm Rockwool Flexi Slab Acoustic Insulation 1200mm x 600mm 92.16m2 Pallet

70mm Rockwool Flexi has been designed as a multi-use, dual-purpose acoustic and thermal mineral wool insulation with a unique flexible edge along one side. It is suitable for use all over the home, in pitched roof rafters, framed external walls, internal partitions, intermediate floors, separating walls and floors, and timber suspended ground floors.

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75mm Knauf Rocksilk RS45 Building Insulation Slab 1200mm x 600mm 4.32m2 Pack

75mm Knauf Insulation Rocksilk RS45 is a Rock Mineral Wool slab, designed for use in multiple thermal and acoustic applications. It is non-combustible with the best possible Euroclass A1 reaction to fire classification.

POA Get a quote

75mm Rockwool Rainscreen Duo Slab 1200mm x 600mm 51.84m2 Pallet

75mm Rainscreen Duo Slab is dual-density insulation specifically developed for use within ventilated cladding systems, as well as sealed systems such as curtain walling. Once installed, the robust outer surface of the slabs, in combination with a factory applied water-repelling agent, acts to resist rain ingress during construction.

POA Get a quote

75mm Rockwool RW3 Acoustic Insulation Slab 1200mm x 600mm 51.84m2 Pallet

75mm Rockwool RW3 Slabs can be applied to an array of general building applications for acoustic, thermal and fire protection of partition walls, ceilings, floors and roofs.

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75mm Rockwool RW4 Acoustic Insulation Slab 1200mm x 600mm 46.08m2 Pallet

75mm Rockwool RW4 Slabs can be applied to an array of general building applications for acoustic, thermal and fire protection of partition walls, ceilings, floors and roofs.

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75mm Rockwool RW5 Acoustic Insulation Slab 1200mm x 600mm 43.20m2 Pallet

75mm Rockwool RW5 Slabs can be applied to an array of general building applications for acoustic, thermal and fire protection of partition walls, ceilings, floors and roofs.

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75mm Superglass Superwall 36 Cavity Wall Slab 5.46m2 Pack

75mm Superglass Superwall 36 Cavity Wall Slab 5.46m2 Pack

75mm Superglass Superwall 36 is non-combustible and water repellent glass mineral wool insulation cavity wall batt. The flexible batt is supplied at 455mm wide to allow easy installation between standard vertical wall tie spacings and minimum on-site cutting and waste.

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90mm Rockwool Flexi Slab Acoustic Insulation 1200mm x 600mm 86.40m2 Pallet

90mm Rockwool Flexi has been designed as a multi-use, dual-purpose acoustic and thermal mineral wool insulation with a unique flexible edge along one side. It is suitable for use all over the home, in pitched roof rafters, framed external walls, internal partitions, intermediate floors, separating walls and floors, and timber suspended ground floors.

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150mm Isover CWS 36 Cavity Wall Slab 3.28m2 Pack

150mm Isover CWS 36 Cavity Wall Slab 3.28m2 Pack

150mm Isover CWS 36 Cavity Wall Slab offers excellent thermal insulation for cavity walls, effectively reducing heat loss and boosting energy efficiency. Lightweight and easy to install, it delivers reliable, long-lasting performance.

£26.91£32.29 Ex VATInc VAT
£8.20£9.84 Per m2 Get restock alert