Where to buy cavity wall insulation?

You can purchase cavity wall insulation online at Insulation Wholesale. We supply an extensive range of partial and full fill cavity wall insulation products for both trade and DIY use. Order online to get a fast quote and volume discounts on pallet quantities, with fast delivery across the UK.

How much does cavity wall insulation cost?

You may pay £15–£30 per square metre of insulation, which varies depending on the region, building type, and insulation material. For an average three-bedroom semi-detached house, you could spend around £700–£1,500 for professional installation. If your property has an unusual wall structure, it may require extra labour, which could raise the overall cost. Avoid unusually low quotes, as poor installation could lead to cold bridging or damp, which may cost more to fix later.

How does cavity wall insulation work?

Insulation for cavity walls is usually made from polystyrene beads, mineral wool or foam. The material is installed in the cavity between the two wall layers to create a barrier that slows down heat transfer. Professional installers often perform a post-installation check using thermal imaging to ensure full coverage.

How does cavity wall insulation reduce heat loss?

When a cavity wall is uninsulated, air moves freely between the wall’s layers. The rate of heat transfer is high as warm air passes through unhindered. Once you fill this space with insulation, air movement is restricted, and heat transfer by radiation and convection is significantly reduced. The insulation traps still air, which acts as a thermal barrier and locks heat inside. So the building stays warmer for longer and requires less energy for heating.

Can cavity wall insulation be removed?

Yes, it can be removed. Removal is typically done when the: Original insulation was incorrectly installed. Wrong insulant was used. Insulation has settled or degraded over time. Property suffers from water ingress or dampness. You need a vacuum extraction system to draw out the insulation through tiny holes drilled in the outer wall. Because of the complexity of the process, it should only be carried out by a professional to avoid damaging the brickwork.

What does cavity wall insulation look like?

Mineral wool insulation is soft, fluffy, and fibrous, and it can appear white or yellowish. Polystyrene beads look like small white balls, similar to foam pellets. Foam insulation expands into a pale yellow or cream semi-solid layer once injected. The insulation is concealed within the cavity and can be confirmed via inspection holes or a borescope survey.

What cavity wall insulation is best?

The best cavity wall insulation depends on the type of property, local weather conditions and budget. Each material offers unique benefits, so choose the one that suits your home’s structure and level of exposure to the elements. Generally, you’ll be choosing from mineral wool, polystyrene and foam options. Mineral wool delivers excellent thermal efficiency, sound insulation and fire resistance. But it can retain moisture, so it’s not ideal for walls exposed to heavy rain without proper weatherproofing. Polystyrene bead insulation combines excellent thermal performance and water resistance, so it is perfect for walls exposed to moisture. The beads flow easily around pipes and corners, nicely filling all spaces. Though more expensive, foam insulation combines superior thermal performance and strength. It expands to fill small gaps and irregular cavities, making it ideal for narrow and hard-to-fill wall cavities. Foam insulation should only be installed by certified professionals due to its chemical expansion properties.

Cavity Wall Insulation At Low Wholesale Price

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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40mm Kingspan Thermawall TW50 PIR Insulation Board 1200mm x 450mm Pack of 12 (6.48m2)

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Kingspan-Thermawall-TW50-Cavity-Wall-PIR-Insulation-Board-Application

40mm Kingspan Thermawall TW50 PIR Insulation Board 1200mm x 450mm Pack of 12 (6.48m2)

40mm Kingspan Thermawall TW50 is a high performance insulation with thermal conductivity of 0.022 W/mK. Therma is a range of PIR insulation available in a range of thicknesses.

£78.62£94.34 Ex VATInc VAT
£12.13£14.56 Per M2 Add to cart

50mm Celotex CW4050 Cavity Wall Insulation Board 1200mm x 450mm 5.94m2 Pack of 11 (5.94m2)

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50mm Celotex CW4050 Cavity Wall Insulation Board 1200mm x 450mm 5.94m2 Pack of 11 (5.94m2)

50mm Celotex CW4050 Cavity Wall Insulation Board is an easy to install polyisocyanurate (PIR) insulation board with excellent thermal performance, featuring a low emissivity foil facing.

£68.25£81.90 Ex VATInc VAT
£11.49£13.79 Per M2 Add to cart

50mm Ecotherm Eco-Cavity Partial Fill Insulation Board 1200mm x 450mm Pack of 10 (5.40m2)

Ecotherm-Partial-Fill-Cavity-Wall-Insulation-Board

Ecotherm-Cavity-Full-Fill-Insulation-Board-Application

50mm Ecotherm Eco-Cavity Partial Fill Insulation Board 1200mm x 450mm Pack of 10 (5.40m2)

50mm Ecotherm Eco-Cavity wall insulation boards are ideal for masonry walls. They achieve high levels of thermal performance for thinner constructions whilst maintaining a clear residual air gap; effective protection against driving rain, particularly in coastal and exposed locations.

POA Get a quote

50mm Kingspan Thermawall TW50 PIR Insulation Board 1200mm x 450mm Pack of 10 (5.40m2)

50mm Kingspan Thermawall TW50 PIR Insulation Board 1200mm x 450mm Pack of 10 (5.40m2)

50mm Kingspan Thermawall TW50 is a high performance insulation with thermal conductivity of 0.022 W/mK. Therma is a range of PIR insulation available in a range of thicknesses.

Non-refundable.

£68.15£81.78 Ex VATInc VAT
£12.62£15.14 Per M2 Add to cart

50mm Recticel Eurowall Partial Cavity Wall Insulation Board 1200mm x 450mm Pack of 20 (10.80m2)

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50mm Recticel Eurowall Partial Cavity Wall Insulation Board 1200mm x 450mm Pack of 20 (10.80m2)

50mm Recticel Eurowall Partial Cavity is an advanced thermal insulation panel tailored for use in cavity wall systems, delivering exceptional energy efficiency and robust performance.

£143.38£172.06 Ex VATInc VAT
£13.28£15.94 Per M2 Add to cart

50mm Unilin T&G XT/CW Partial Fill Cavity Wall Insulation Board 1200mm x 450mm Pallet of 225 (121.50m2)

50mm Unilin Thin-R XT/CW Partial Fill Cavity Wall Insulation (T&G) is typically used in external walls of buildings with cavity wall construction.

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60mm Celotex CW4060 Cavity Wall Insulation Board 1200mm x 450mm 5.4m2 Pack of 10

60mm Celotex CW4060 Cavity Wall Insulation Board 1200mm x 450mm 5.4m2 Pack of 10

60mm Celotex CW4060 Cavity Wall Insulation Board is an easy to install polyisocyanurate (PIR) insulation board with excellent thermal performance, featuring a low emissivity foil facing.

£71.70£86.04 Ex VATInc VAT
£13.28£15.94 Per M2 Add to cart

60mm Ecotherm Eco-Cavity Partial Fill Insulation Board 1200mm x 450mm Pack of 8 (4.32m2)

60mm Ecotherm Eco-Cavity Partial Fill Insulation Board 1200mm x 450mm Pack of 8 (4.32m2)

60mm Ecotherm Eco-Cavity wall insulation boards are ideal for masonry walls. They achieve high levels of thermal performance for thinner constructions whilst maintaining a clear residual air gap; effective protection against driving rain, particularly in coastal and exposed locations.

POA Get a quote

60mm Kingspan Thermawall TW50 PIR Insulation Board 1200mm x 450mm Pack of 8 (4.32m2)

60mm Kingspan Thermawall TW50 PIR Insulation Board 1200mm x 450mm Pack of 8 (4.32m2)

60mm Kingspan Thermawall TW50 is a high performance insulation with thermal conductivity of 0.022 W/mK. Therma is a range of PIR insulation available in a range of thicknesses.

£66.41£79.69 Ex VATInc VAT
£15.37£18.44 Per M2 Add to cart

60mm Recticel Eurowall Partial Cavity Wall Insulation Board 1200mm x 450mm Pack of 16 (8.64m2)

60mm Recticel Eurowall Partial Cavity Wall Insulation Board 1200mm x 450mm Pack of 16 (8.64m2)

60mm Recticel Eurowall offers rigid great performance insulation boards designed for partial cavity walls. They lock in warmth and boost energy efficiency with ease.

£132.26£158.71 Ex VATInc VAT
£15.31£18.37 Per M2 Add to cart

70mm Kingspan Thermawall TW50 PIR Insulation Board 1200mm x 450mm Pack of 6 (3.24m2)

70mm Kingspan Thermawall TW50 PIR Insulation Board 1200mm x 450mm Pack of 6 (3.24m2)

70mm Kingspan Thermawall TW50 is a high performance insulation with thermal conductivity of 0.022 W/mK. Therma is a range of PIR insulation available in a range of thicknesses.

£57.58£69.10 Ex VATInc VAT
£17.77£21.32 Per M2 Add to cart

70mm Recticel Eurowall Partial Cavity Wall Insulation Board 1200mm x 450mm Pack of 14 (7.56m2)

70mm Recticel Eurowall Partial Cavity Wall Insulation Board 1200mm x 450mm Pack of 14 (7.56m2)

70mm Recticel Eurowall Partial Cavity is an advanced thermal insulation panel tailored for use in cavity wall systems, delivering exceptional energy efficiency and robust performance.

£127.81£153.37 Ex VATInc VAT
£16.91£20.29 Per M2 Add to cart

75mm Celotex CW4075 Cavity Wall Insulation Board 1200mm x 450mm 4.32m2 Pack of 8 (4.32m2)

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75mm Celotex CW4075 Cavity Wall Insulation Board 1200mm x 450mm 4.32m2 Pack of 8 (4.32m2)

75mm Celotex CW4075 Cavity Wall Insulation Board is an easy to install polyisocyanurate (PIR) insulation board with excellent thermal performance, featuring a low emissivity foil facing.

£66.13£79.36 Ex VATInc VAT
£15.31£18.37 Per M2 Add to cart

75mm Ecotherm Eco-Cavity Partial Fill Insulation Board 1200mm x 450mm Pack of 6 (3.24m2)

75mm Ecotherm Eco-Cavity Partial Fill Insulation Board 1200mm x 450mm Pack of 6 (3.24m2)

75mm Ecotherm Eco-Cavity wall insulation boards are ideal for masonry walls. They achieve high levels of thermal performance for thinner constructions whilst maintaining a clear residual air gap; effective protection against driving rain, particularly in coastal and exposed locations.

POA Get a quote

75mm Kingspan Thermawall TW50 PIR Insulation Board 1200mm x 450mm Pack of 6 (3.24m2)

75mm Kingspan Thermawall TW50 PIR Insulation Board 1200mm x 450mm Pack of 6 (3.24m2)

75mm Kingspan Thermawall TW50 is a high performance insulation with thermal conductivity of 0.022 W/mK. Therma is a range of PIR insulation available in a range of thicknesses.

£58.33£70.00 Ex VATInc VAT
£18.00£21.60 Per M2 Add to cart

75mm Recticel Eurowall Partial Cavity Wall Insulation Board 1200mm x 450mm Pack of 12 (6.48m2)

75mm Recticel Eurowall Partial Cavity Wall Insulation Board 1200mm x 450mm Pack of 12 (6.48m2)

75mm Recticel Eurowall offers rigid great performance insulation boards designed for partial cavity walls. They lock in warmth and boost energy efficiency with ease.

£106.38£127.66 Ex VATInc VAT
£16.42£19.70 Per M2 Add to cart

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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80mm Recticel Eurowall Partial Cavity Wall Insulation Board 1200mm x 450mm Pack of 12 (6.48m2)

80mm Recticel Eurowall Partial Cavity Wall Insulation Board 1200mm x 450mm Pack of 12 (6.48m2)

80mm Recticel Eurowall offers rigid great performance insulation boards designed for partial cavity walls. They lock in warmth and boost energy efficiency with ease.

£121.91£146.29 Ex VATInc VAT
£18.81£22.57 Per M2 Add to cart

80mm Unilin XT/CW Partial Fill Cavity Wall Insulation Board 1200mm x 450mm Pallet of 125 (67.50m2)

80mm Unilin Thin-R XT/CW Partial Fill Cavity Wall Insulation (S&E) is typically used in external walls of buildings with cavity wall construction.

POA Get a quote

90mm Celotex Thermaclass Cavity Wall 21 Insulation Board 1190mm x 450mm Pack of 6 (3.21m2)

Celotex-Full-Fill-Cavity-Wall-Application

90mm Celotex Thermaclass Cavity Wall 21 Insulation Board 1190mm x 450mm Pack of 6 (3.21m2)

90mm Celotex Thermaclass Cavity Wall 21 is a PIR T&G insulation board designed for full-fill cavity wall applications. Low-emissivity foil facing provides versatility during installation, allowing for a 10mm residual cavity.

£122.68£147.22 Ex VATInc VAT
£38.22£45.86 Per M2 Add to cart

90mm Ecotherm Eco-Cavity Full Fill Insulation Board Tongue And Groove 1200mm x 450mm Pack of 4 (2.16m2)

Ecotherm-Full-Fill-Cavity-Wall-Insulation-Board copy

Eoctherm-Full-Fill-Cavity Board-Insulation-Board-Application-Wall

90mm Ecotherm Eco-Cavity Full Fill Insulation Board Tongue And Groove 1200mm x 450mm Pack of 4 (2.16m2)

Eco-Cavity Full Fill is suitable for full fill cavity wall applications while maintaining a residual 10 mm cavity. The residual cavity helps resist moisture transfer, aids installation, and accommodates mortar squeeze. The tongue and groove edges to ensure a continuous layer of insulation, increasing protection from wind driven rain and aiding installation.

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90mm Recticel Eurowall Full Fill Cavity Wall Insulation Board 1200mm x 460mm Pack of 10 (5.52m2)

90mm Recticel Eurowall T&G Full Fill Cavity is an advanced thermal insulation panel tailored for use in cavity wall systems, delivering exceptional energy efficiency and robust performance.

£136.64£163.97 Ex VATInc VAT
£24.75£29.70 Per M2 Get restock alert

90mm Recticel Eurowall Partial Cavity Wall Insulation Board 1200mm x 450mm Pack of 10 (5.40m2)

90mm Recticel Eurowall Partial Cavity Wall Insulation Board 1200mm x 450mm Pack of 10 (5.40m2)

90mm Recticel Eurowall offers rigid great performance insulation boards designed for partial cavity walls. They lock in warmth and boost energy efficiency with ease.

£120.94£145.13 Ex VATInc VAT
£22.40£26.88 Per M2 Get restock alert