What is internal wall insulation?

Internal wall insulation is the material used to add a thermal layer to solid-walled homes. It is especially useful for older solid wall houses and is commonly available as PIR boards, EPS panels, and mineral wool.

How much does internal wall insulation cost?

The total cost depends on material choice and project size. Prices are usually calculated per square metre for both boards and rolls. They can start as low as £2-£3 and climb to £49 or more per m². These prices typically refer to supply only; installation costs are additional.

How thick should internal wall insulation be?

Thickness varies depending on the material and available space. Thicker insulation provides better thermal resistance, but consider whether you have enough space for it. For optimal performance, a thickness range of 50 - 100mm applies to PIR boards. EPS boards require 75 - 100mm, while mineral wool slabs and rolls require 100 - 150mm. Consider getting a recommendation for optimal insulation thickness from a qualified installer. Thicker insulation improves U-values by reducing heat loss through the wall.

How to fit internal wall insulation?

You can fit insulation on interior walls using two methods. In both, the walls should be clean and dry before adding the insulant. Direct Fix: This is where you attach the boards directly to the wall and add a finish of your liking. Batten and Frame: Here, you fix timber or metal studs to the wall, insert the insulation slab or roll, then cover with plasterboard. Improper installation can lead to interstitial condensation; always use a vapour control layer where required. If unsure of doing a perfect installation, consult a qualified installer to avoid condensation or cold bridging issues.

Internal Wall Insulation At Low Wholesale Prices

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Products in Internal Wall Insulation

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90mm IKO Enertherm ALU PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

90mm IKO Enertherm ALU PIR (polyisocyanurate) insulation is a top-quality insulation board featuring a rigid PIR foam core and reflective aluminium foil facings. It delivers outstanding thermal performance and moisture resistance, making it suitable for various installations and an ideal choice for different energy-efficient projects.

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90mm Kingspan Therma TP10 / TF70 / TW55 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pack of 3 (8.64m2)
All three models 90mm Kingspan Therma PIR Insulation Board:
- 90mm Thermapitch TP10
- 90mm Thermafloor TF70
- 90mm Thermawall TW55
share the same high-performance PIR core and low-emissivity foil facings, offering excellent thermal efficiency and easy installation. Although labeled differently, these boards share identical technical specifications.
£165.03£198.04 Ex VATInc VAT
£19.10£22.92 Per M2 Add to cart
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90mm Mannok PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

90mm Mannok PIR Insulation Board is an excellent choice for anyone looking for a high-performance insulation solution that provides superior thermal efficiency. It is ideal for use in any construction project, such as commercial and residential, in wall applications as well as roofing and flooring applications.

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90mm Recticel Eurothane Eurodeck Insulation Board 2400mm x 1200mm Pack of 5 (14.40m2)

90mm Eurothane^® Eurodeck is compatible with mechanically fixed single-ply systems, benefiting from high compressive strength and excellent dimensional stability that ensures the flat surface finish required for optimum performance in new build and refurbishment projects. It is faced on both sides with a multi-layer coated aluminum foil.

£270.21£324.25 Ex VATInc VAT
£18.76£22.51 Per M2 Add to cart
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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90mm Unilin Thin-R PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pallet of 24 (69.12m2)

90mm Unilin Thin-R PIR insulation is a foil faced, high-performance insulation solution that offers exceptional thermal efficiency and durability. This polyisocyanurate insulation board, formerly known as Xtratherm, is ideal for a range of applications, such as floors, pitched roofs, and walls.

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125mm Mannok PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

125mm Mannok PIR Insulation Board is an excellent choice for anyone looking for a high-performance insulation solution that provides superior thermal efficiency. It is ideal for use in any construction project, such as commercial and residential, in wall applications as well as roofing and flooring applications.

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100mm Kingspan Kooltherm K112 Framing Insulation Board 2400mm x 1200mm Pack of 3 (8.64m2)

100mm Kingspan Kooltherm K112 Framing Board is a premium performance insulation with a fibre-free rigid thermoset phenolic core. It is used to insulate timber and steel framing systems with thermal conductivity of just 0.019 W/mK across all thicknesses.

£409.37£491.24 Ex VATInc VAT
£47.38£56.86 Per M2 Get restock alert
130mm Recticel Eurothane GP PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2

130mm Recticel Eurothane GP is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Recticel is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.

£56.17£67.40 Ex VATInc VAT
£19.50£23.40 Per M2 Get restock alert
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20mm Kingspan Therma TP10 / TF70 / TW55 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pack of 15 (43.20m2)
All three models 20mm Kingspan Therma PIR Insulation Board:
- 20mm Thermapitch TP10
- 20mm Thermafloor TF70
- 20mm Thermawall TW55
share the same high-performance PIR core and low-emissivity foil facings, offering excellent thermal efficiency and easy installation. Although labeled differently, these boards share identical technical specifications.

No longer in production.
£326.73£392.08 Ex VATInc VAT
£7.56£9.07 Per M2 Get restock alert
60mm Superglass Multi Acoustic Roll Insulation 13.50m2 Roll

60mm Superglass Acoustic Partition Roll (APR) is a lightweight, non-combustible glass mineral wool insulation roll. It is suitable for the following applications: internal walls and floors, timber and metal stud partitions, drylining systems and separating walls and floors. Manufactured at a minimum density of 10kg/m³.

£29.41£35.29 Ex VATInc VAT
£2.18£2.62 Per m2 Get restock alert
80mm Superglass Multi Acoustic Roll Insulation 12.48m2 Roll

80mm Superglass Acoustic Partition Roll (APR) is a lightweight, non-combustible glass mineral wool insulation roll. It is suitable for the following applications: internal walls and floors, timber and metal stud partitions, drylining systems and separating walls and floors. Manufactured at a minimum density of 10kg/m³.

£40.15£48.18 Ex VATInc VAT
£3.22£3.86 Per m2 Get restock alert