Pitched Roof Insulation
Pitched roof insulation is the key to maintaining a warm, energy-efficient home or workspace. Using specialised insulating material to seal off one of the most significant areas of possible heat loss helps transform roof spaces into cosy, usable environments.
What is insulation for pitched roofs?
It is a thermal layer fitted within the roof structure. Depending on the project, the insulating material is fitted between rafters, above rafters, or below them. Between-rafter systems are the most common in UK homes because they balance excellent performance with ease of installation.
These insulation systems are designed to contain temperature fluctuations and control moisture. They create a thermal barrier and protect against cold draughts and excessive heat.
What is pitched roof insulation used for?
Insulation for pitched roofs contributes to:
- Thermal protection for loft conversions and attic refurbishments.
- Boosting thermal stability in new-build pitched roof systems.
- Delivering energy upgrades in older properties.
- Reducing noise in living spaces directly under the roof.
Types of suitable insulation for pitched roofs
We have several effective materials that work well for pitched roofs, including:
- PIR insulation panels: Lightweight and rigid. Commonly used between or under rafters for excellent thermal resistance.
- Phenolic insulation foam panels: Slim yet efficient. Ideal for space-constrained areas.
- Mineral wool rolls or slabs: Great for acoustic control, flexibility, and fire resistance. They are commonly installed between rafters. Perfect for lofts.
- Multifoil insulation: Reflective layers that help manage radiant heat. Often combined with other insulation types.
A popular choice among professionals is Kingspan Kooltherm K107 Pitched Roof Board. It offers outstanding thermal efficiency and moisture resistance in a slim build and is among the most reliable insulating products in the UK, depending on the application.
Benefits of pitched roof insulation
Here is what quality insulation can do for your roof and property:
- Enhances efficient use of energy.
- Increases thermal comfort throughout the home.
- Cuts heating bills.
- Prevents condensation and moisture damage in the roof space.
- Reduces external noise transmission.
- Extends the roof’s lifespan by protecting it from temperature fluctuations.
- Supports compliance with UK Building Regulations.
- Improves EPC ratings.
- Increases property value with long-term energy savings.
Why choose our insulation for pitched roofs?
Insulation Wholesale only sources the highest-performing pitched roof insulation products from trusted UK brands. You’ll benefit from:
- Top-quality materials built for professional results.
- Expert technical advice for trade or DIY projects.
- Competitive prices across the full range.
- Friendly support to help you select the right thickness and type for your roof.
- Fast, reliable delivery nationwide (usually within 1–3 working days, unless otherwise indicated on the product page or at checkout).
- Complete systems and accessories for a perfect fit.
Whether you’re insulating between rafters or upgrading an old system, we’ll help you pick the ideal solution for your pitched roof. Shop our full range of pitched roof insulation online now or contact our team for tailored advice.
FAQ
What is pitched roof insulation?
This is a layer of thermal material installed along the sloped surfaces of pitched roofs. It counters heat loss and ensures efficient energy use. You may fit pitched roof insulation on new buildings or retrofits to ensure continued comfort and efficiency.
How to install pitched roof insulation?
Installation varies slightly depending on the insulation system:
- Between rafters: Cut boards to fit snugly between rafters.
- Under rafters: Fix the insulation below the structure for continuous coverage.
- Above rafters: Use rigid boards on the deck for maximum performance.
Once you are confident you have installed the material correctly, seal all gaps with airtight tape or low-expanding foam and place your vapour control layer correctly. Ensure adequate ventilation in cold roof designs to impede moisture build-up.
What thickness insulation for pitched roof?
The ideal thickness is determined by your roof design and target U-value. For most UK applications, 130mm–180 mm of PIR or phenolic board achieves a U-value around 0.18 W/m²K, which is the current Building Regulations standard. Mineral wool may need greater depth to perform similarly.
Showing 1–32 of 168 results
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100mm Kingspan Kooltherm K107 Pitched Roof Board 2400mm x 1200mm Pack of 3 (8.64m2)
100mm Kingspan Kooltherm K107 Pitched Roof Board is a premium performance insulation with a fibre-free rigid thermoset phenolic core. It is used to insulate pitched roofs and attic spaces, and has a thermal conductivity of just 0.019 W/m.K across all thicknesses.
£332.12£398.54 Ex VATInc VAT£38.44£46.13 Per M2 Add to cart -
100mm Rockwool Flexi Slab Acoustic Insulation 1200mm x 600mm 4.32m2 Pack
100mm 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.
£40.41£48.49 Ex VATInc VAT£9.35£11.22 Per m2 Add to cart -
100mm Rockwool RWA45 Acoustic Insulation Slab 1200 x 600mm 2.88m2 Pack
100mm 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.
£21.39£25.67 Ex VATInc VAT£7.43£8.92 Per m2 Add to cart -
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.
POA Get a quote -
120mm Kingspan Kooltherm K107 Pitched Roof Board 2400mm x 1200mm Pack of 2 (5.76m2)
120mm Kingspan Kooltherm K107 Pitched Roof Board is a premium performance insulation with a fibre-free rigid thermoset phenolic core. It is used to insulate pitched roofs and attic spaces, and has a thermal conductivity of just 0.019 W/m.K across all thicknesses.
£260.24£312.29 Ex VATInc VAT£45.18£54.22 Per M2 Add to cart -
140mm Rockwool Flexi Slab Acoustic Insulation 1200mm x 600mm 2.88m2 Pack
140mm 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.
£37.80£45.36 Ex VATInc VAT£13.13£15.76 Per m2 Add to cart -
25mm Kingspan Kooltherm K107 Pitched Roof Board 2400mm x 1200mm Pack of 12 (34.56m2)
25mm Kingspan Kooltherm K107 Pitched Roof Board is a premium performance insulation with a fibre-free rigid thermoset phenolic core. It is used to insulate pitched roofs and attic spaces, and has a thermal conductivity of just 0.019 W/m.K across all thicknesses.
£449.82£539.78 Ex VATInc VAT£13.02£15.62 Per M2 Add to cart -
37.5mm Kingspan Kooltherm K118 Insulated Plasterboard 2400mm x 1200mm Pack of 21 (60.48m2)
25mm + 12.5mm Kingspan Kooltherm K118 Insulated Plasterboard is a premium performance insulation with a fibre-free rigid thermoset phenolic core. It is an insulated plasterboard for mechanically fixed and adhesively bonded insulated dry-lining th a thermal conductivity of just 0.019 W/mK across all thicknesses.
£1,451.52£1,741.82 Ex VATInc VAT£24.00£28.80 Per M2 Add to cart -
42.5mm Kingspan Kooltherm K118 Insulated Plasterboard 2400mm x 1200mm Pack of 18 (51.84m2)
30mm + 12.5mm Kingspan Kooltherm K118 Insulated Plasterboard is a premium performance insulation with a fibre-free rigid thermoset phenolic core. It is an insulated plasterboard for mechanically fixed and adhesively bonded insulated dry-lining th a thermal conductivity of just 0.019 W/mK across all thicknesses.
£1,283.25£1,539.90 Ex VATInc VAT£24.75£29.70 Per M2 Add to cart -
50mm Kingspan Kooltherm K107 Pitched Roof Board 2400mm x 1200mm Pack of 6 (17.28m2)
50mm Kingspan Kooltherm K107 Pitched Roof Board is a premium performance insulation with a fibre-free rigid thermoset phenolic core. It is used to insulate pitched roofs and attic spaces, and has a thermal conductivity of just 0.019 W/m.K across all thicknesses.
£347.95£417.54 Ex VATInc VAT£20.14£24.17 Per M2 Add to cart -
50mm Rockwool RWA45 Acoustic Insulation Slab 1200 x 600mm 6.48m2 Pack
50mm 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.
£26.95£32.34 Ex VATInc VAT£4.16£4.99 Per m2 Add to cart -
52.5mm Kingspan Kooltherm K118 Insulated Plasterboard 2400mm x 1200mm Pack of 15 (43.20m2)
40mm + 12.5mm Kingspan Kooltherm K118 Insulated Plasterboard is a premium performance insulation with a fibre-free rigid thermoset phenolic core. It is an insulated plasterboard for mechanically fixed and adhesively bonded insulated dry-lining th a thermal conductivity of just 0.019 W/mK across all thicknesses.
£1,132.70£1,359.24 Ex VATInc VAT£26.22£31.46 Per M2 Add to cart -
57.5mm Kingspan Kooltherm K118 Insulated Plasterboard 2400mm x 1200mm Pack of 14 (40.32m2)
45mm + 12.5mm Kingspan Kooltherm K118 Insulated Plasterboard is a premium performance insulation with a fibre-free rigid thermoset phenolic core. It is an insulated plasterboard for mechanically fixed and adhesively bonded insulated dry-lining th a thermal conductivity of just 0.019 W/mK across all thicknesses.
£1,131.07£1,357.28 Ex VATInc VAT£28.05£33.66 Per M2 Add to cart -
60mm Kingspan Kooltherm K107 Pitched Roof Board 2400mm x 1200mm Pack of 5 (14.40m2)
60mm Kingspan Kooltherm K107 Pitched Roof Board is a premium performance insulation with a fibre-free rigid thermoset phenolic core. It is used to insulate pitched roofs and attic spaces, and has a thermal conductivity of just 0.019 W/m.K across all thicknesses.
£345.30£414.36 Ex VATInc VAT£23.98£28.78 Per M2 Add to cart -
62.5mm Kingspan Kooltherm K118 Insulated Plasterboard 2400mm x 1200mm Pack of 12 (34.56m2)
50mm + 12.5mm Kingspan Kooltherm K118 Insulated Plasterboard is a premium performance insulation with a fibre-free rigid thermoset phenolic core. It is an insulated plasterboard for mechanically fixed and adhesively bonded insulated dry-lining th a thermal conductivity of just 0.019 W/mK across all thicknesses.
£1,033.91£1,240.69 Ex VATInc VAT£29.92£35.90 Per M2 Add to cart -
70mm Kingspan Kooltherm K107 Pitched Roof Board 2400mm x 1200mm Pack of 4 (11.52m2)
70mm Kingspan Kooltherm K107 Pitched Roof Board is a premium performance insulation with a fibre-free rigid thermoset phenolic core. It is used to insulate pitched roofs and attic spaces, and has a thermal conductivity of just 0.019 W/m.K across all thicknesses.
£321.11£385.33 Ex VATInc VAT£27.87£33.44 Per M2 Add to cart -
72.5mm Kingspan Kooltherm K118 Insulated Plasterboard 2400mm x 1200mm Pack of 11 (31.68m2)
60mm + 12.5mm Kingspan Kooltherm K118 Insulated Plasterboard is a premium performance insulation with a fibre-free rigid thermoset phenolic core. It is an insulated plasterboard for mechanically fixed and adhesively bonded insulated dry-lining th a thermal conductivity of just 0.019 W/mK across all thicknesses.
£995.84£1,195.01 Ex VATInc VAT£31.43£37.72 Per M2 Add to cart -
75mm Kingspan Kooltherm K107 Pitched Roof Board 2400mm x 1200mm Pack of 4 (11.52m2)
75mm Kingspan Kooltherm K107 Pitched Roof Board is a premium performance insulation with a fibre-free rigid thermoset phenolic core. It is used to insulate pitched roofs and attic spaces, and has a thermal conductivity of just 0.019 W/m.K across all thicknesses.
£343.06£411.67 Ex VATInc VAT£29.78£35.74 Per M2 Add to cart -
75mm Rockwool RWA45 Acoustic Insulation Slab 1200 x 600mm 4.32m2 Pack
75mm 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.
£25.87£31.04 Ex VATInc VAT£5.99£7.19 Per m2 Add to cart -
80mm Kingspan Kooltherm K107 Pitched Roof Board 2400mm x 1200mm Pack of 4 (11.52m2)
80mm Kingspan Kooltherm K107 Pitched Roof Board is a premium performance insulation with a fibre-free rigid thermoset phenolic core. It is used to insulate pitched roofs and attic spaces, and has a thermal conductivity of just 0.019 W/m.K across all thicknesses.
£364.77£437.72 Ex VATInc VAT£31.66£37.99 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-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.
£221.26£265.51 Ex VATInc VAT£25.61£30.73 Per M2 Add to cart -
100mm Knauf Rocksilk RS45 Building Insulation Slab 1200mm x 600mm 3.6m2 Pack
100mm 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 -
100mm Mannok PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
100mm 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.
POA Get a quote -
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.
£42.43£50.92 Ex VATInc VAT£14.73£17.68 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 -
110mm Mannok PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
110mm 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.
POA Get a quote -
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-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











































