120mm 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.
Insulation Board By Thickness Thermal
Insulation board by thickness focuses on picking the right board depth for each application, rather than focusing solely on brands or materials. This category allows you to compare insulation thicknesses side by side. This makes it easier to choose insulation that fits each space and gives the performance required for the build.
What is insulation board thickness?
Insulation board thickness means the insulation board’s actual depth. Thickness is especially useful when space is limited or where drawings specify a precise insulation size.
This category groups insulation boards by different thicknesses. Browse the listed products and compare options like 25mm, 50mm, 75mm, 100mm, and above in one place.
What are the different insulation board thicknesses used for?
Different insulation board thicknesses are suited to different parts of a building and performance requirements.
Thinner insulation boards (15–42.5mm)
Best for internal wall lining and within floor build-ups where space is limited. Also used to upgrade insulation without moving windows or doors. They enhance thermal performance without major changes to the structure.
Mid-range boards (50–100mm)
Ideal for walls, floors, and roofs. Often used in refurbishments and extensions where a balance between thermal performance and build-up is required.
Thicker insulation board options (110–200mm)
These thicknesses are preferred for roofs and external walls. Thick insulation boards provide stronger resistance to heat loss, helping meet current UK Building Regulations and energy-efficiency targets.
Benefits of choosing the right insulation board thickness
Varying insulation thicknesses give builders and homeowners great flexibility when upgrading or designing a property.
For instance, older homes were not designed with modern insulation in mind. Being able to choose thinner or mid-range boards makes it possible to upgrade spaces without major disruption to the existing structure. On the other hand, new builds benefit from thicker options that maximise energy efficiency from day one.
Different thicknesses also help balance:
- Thermal performance – how well heat transfer is slowed.
- Available space – what will physically fit.
- Cost control – thicker is not always necessary for every area.
It becomes easier to combine a range of insulation board thicknesses across a project so you do not over-insulate one area and under-insulate another.
FAQ
Where to buy Insulation board by thickness?
You can buy all insulation Board thicknesses right here at Insulation Wholesale. We stock a wide range of insulation boards by thickness, so you do not have to compromise on material depth. Our team understands the importance of clear sizing and reliable stock. Order your preferred insulation thickness Board online for competitive pricing and fast delivery.
What insulation board thicknesses are there?
Insulation boards commonly range from 20mm to 150mm and above. Some brands offer higher thicknesses beyond 150mm, reaching 200mm and thicker for custom orders. In this category, all our boards are grouped by thickness for easy comparison.
What is the thickest insulation board available?
The thickest insulation is 120mm to 200mm and thicker, mainly used in roofs, external walls, and high-performance builds where energy efficiency is a priority. These thicknesses offer significantly higher resistance to heat loss.
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15mm Insulation Board (1)
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20mm Insulation Board (6)
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25mm Insulation Board (24)
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27mm Insulation Board (1)
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30mm Insulation Board (14)
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37.5mm Insulation Board (5)
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40mm Insulation Board (15)
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42.5mm Insulation Board (1)
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50mm Insulation Board (38)
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50.5mm Insulation Board (1)
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52.5mm Insulation Board (5)
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57.5mm Insulation Board (1)
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60mm Insulation Board (28)
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62.5mm Insulation Board (6)
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70mm Insulation Board (15)
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72.5mm Insulation Board (5)
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75mm Insulation Board (23)
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80mm Insulation Board (25)
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82.5mm Insulation Board (3)
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90mm Insulation Board (19)
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92.5mm Insulation Board (1)
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100mm Insulation Board (35)
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110mm Insulation Board (10)
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115mm Insulation Board (3)
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120mm Insulation Board (22)
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125mm Insulation Board (4)
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130mm Insulation Board (15)
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140mm Insulation Board (16)
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150mm Insulation Board (22)
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165mm Insulation Board (2)
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200mm Insulation Board (1)
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110mm Unilin Thin-R PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pallet of 21 (60.48m2)
110mm 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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100mm Celotex CW4100 Cavity Wall Insulation Board 1200mm x 450mm 3.24m2 Pack of 6 (3.24m2)
100mm Celotex CW4100 Cavity Wall Insulation Board is an easy to install polyisocyanurate (PIR) insulation board with excellent thermal performance, featuring a low emissivity foil facing.
£63.73£76.48 Ex VATInc VAT£19.67£23.60 Per M2 Add to cart -
100mm Celotex GA4100 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
100mm Celotex GA4100 is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Celotex is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.
£44.37£53.24 Ex VATInc VAT£15.41£18.49 Per M2 Add to cart -
100mm Ecotherm Eco-Bond PIR Insulation Board 1200mm x 1200mm (4′ x 4′) Pack of 4 (5.76m2)
100mm Eco-Bond PIR insulation boards provide a lightweight, easy-to-install solution for new roofs or upgrading existing ones. Ideal for use with fully adhered single-ply waterproofing on concrete, metal, and timber decks.
POA Get a quote -
100mm Ecotherm Eco-Cavity Partial Fill Insulation Board 1200mm x 450mm Pack of 5 (2.70m2)
100mm 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.
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100mm Ecotherm Eco-Torch PIR Insulation Board 1200mm x 600mm (4′ x 2′) Pack of 5 (3.60m2)
100mm Eco-Torch PIR Insulation Board is a flexible insulation option, perfect for torch-on, roll-and-pour felt systems, mastic asphalt, and single-ply systems.
POA Get a quote -
100mm Ecotherm Eco-Versal Rigid PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
100mm Ecotherm Eco-Versal is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Ecotherm Eco-Versal is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.
£39.67£47.60 Ex VATInc VAT£13.77£16.52 Per M2 Add to cart -
100mm IKO Enertherm ALU PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
100mm 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.
POA Get a quote -
100mm Kingspan Therma TP10 / TF70 / TW55 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pack of 3 (8.64m2)
All three models 100mm Kingspan Therma PIR Insulation Board:
- 100mm Thermapitch TP10
- 100mm Thermafloor TF70
- 100mm 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.
£176.72£212.06 Ex VATInc VAT£20.45£24.54 Per M2 Add to cart -
100mm Recticel Eurothane GP PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
100mm 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.
£38.61£46.33 Ex VATInc VAT£13.41£16.09 Per M2 Add to cart -
100mm Unilin Thin-R PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pallet of 24 (69.12m2)
100mm 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.
POA Get a quote -
110mm IKO Enertherm ALU PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
110mm 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.
POA Get a quote -
115mm Celotex Thermaclass Cavity Wall 21 Insulation Board 1190mm x 450mm Pack of 5 (2.67m2)
115mm 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.
£137.98£165.58 Ex VATInc VAT£51.68£62.02 Per M2 Add to cart -
115mm 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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120mm Celotex XR4120 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
120mm Celotex XR4120 is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Celotex is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.
£55.16£66.19 Ex VATInc VAT£19.15£22.98 Per M2 Add to cart -
120mm Ecotherm Eco-Bond PIR Insulation Board 1200mm x 1200mm (4′ x 4′) Pack of 4 (5.76m2)
120mm Eco-Bond PIR insulation boards provide a lightweight, easy-to-install solution for new roofs or upgrading existing ones. Ideal for use with fully adhered single-ply waterproofing on concrete, metal, and timber decks.
POA Get a quote -
120mm Ecotherm Eco-Torch PIR Insulation Board 1200mm x 600mm (4′ x 2′) Pack of 4 (2.88m2)
120mm Eco-Torch PIR Insulation Board is a flexible insulation option, perfect for torch-on, roll-and-pour felt systems, mastic asphalt, and single-ply systems.
POA Get a quote -
120mm Ecotherm Eco-Versal Rigid PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
120mm Ecotherm Eco-Versal is a polyisocyanurate (PIR) insulation core with composite aluminium foil facings on both sides. Ecotherm Eco-Versal is a multi-purpose insulation board suitable for use in pitched roofs, ceilings, floors and walls.
£49.85£59.82 Ex VATInc VAT£17.31£20.77 Per M2 Add to cart -
120mm IKO Enertherm ALU PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
120mm 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.
POA Get a quote -
120mm Recticel Eurothane GP PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
120mm 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.
£47.62£57.14 Ex VATInc VAT£16.53£19.84 Per M2 Add to cart -
125mm Kingspan Therma TP10 / TF70 / TW55 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pack of 2 (5.76m2)
All three models 20mm Kingspan Therma PIR Insulation Board:
- 125mm Thermapitch TP10
- 125mm Thermafloor TF70
- 125mm 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.
£204.71£245.65 Ex VATInc VAT£35.54£42.65 Per M2 Add to cart -
125mm Unilin Thin-R PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pallet of 18 (51.84m2)
125mm 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.
POA Get a quote -
130mm Ecotherm Eco-Bond PIR Insulation Board 1200mm x 1200mm (4′ x 4′) Pack of 3 (4.32m2)
130mm Eco-Bond PIR insulation boards provide a lightweight, easy-to-install solution for new roofs or upgrading existing ones. Ideal for use with fully adhered single-ply waterproofing on concrete, metal, and timber decks.
POA Get a quote -
130mm Ecotherm Eco-Torch PIR Insulation Board 1200mm x 600mm (4′ x 2′) Pack of 3 (2.16m2)
130mm Eco-Torch PIR Insulation Board is a flexible insulation option, perfect for torch-on, roll-and-pour felt systems, mastic asphalt, and single-ply systems.
POA Get a quote -
130mm Unilin Thin-R PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pallet of 18 (51.84m2)
130mm 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.
POA Get a quote -
140mm Ecotherm Eco-Bond PIR Insulation Board 1200mm x 1200mm (4′ x 4′) Pack of 2 (2.88m2)
140mm Eco-Bond PIR insulation boards provide a lightweight, easy-to-install solution for new roofs or upgrading existing ones. Ideal for use with fully adhered single-ply waterproofing on concrete, metal, and timber decks.
POA Get a quote






































