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 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.
£26.67£32.00 Ex VATInc VAT£9.26£11.11 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.
£26.67£32.00 Ex VATInc VAT£9.26£11.11 Per M2 Add to cart -
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.
£289.16£346.99 Ex VATInc VAT£33.47£40.16 Per M2 Add to cart -
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.
£138.93£166.72 Ex VATInc VAT£16.08£19.30 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.
£26.67£32.00 Ex VATInc VAT£9.26£11.11 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 Celotex XR4110 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
110mm Celotex XR4110 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.
£32.42£38.90 Ex VATInc VAT£11.26£13.51 Per M2 Add to cart -
110mm Ecotherm Eco-Versal Rigid PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
110mm 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.
£32.42£38.90 Ex VATInc VAT£11.26£13.51 Per M2 Add to cart -
110mm Recticel Eurothane GP PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
110mm 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.
£32.42£38.90 Ex VATInc VAT£11.26£13.51 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 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.
£32.75£39.30 Ex VATInc VAT£11.37£13.64 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.
£32.44£38.93 Ex VATInc VAT£11.26£13.51 Per M2 Add to cart -
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.
£235.38£282.46 Ex VATInc VAT£40.86£49.03 Per M2 Add to cart -
120mm Kingspan Therma TP10 / TF70 / TW55 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pack of 2 (5.76m2)
All three models 120mm Kingspan Therma PIR Insulation Board:
- 120mm Thermapitch TP10
- 120mm Thermafloor TF70
- 120mm 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.
£111.30£133.56 Ex VATInc VAT£19.32£23.18 Per M2 Add to cart -
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.
£32.44£38.93 Ex VATInc VAT£11.26£13.51 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.
£128.56£154.27 Ex VATInc VAT£22.32£26.78 Per M2 Add to cart -
130mm Celotex XR4130 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
130mm Celotex XR4130 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.
£38.80£46.56 Ex VATInc VAT£13.47£16.16 Per M2 Add to cart -
130mm Ecotherm Eco-Versal Rigid PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
130mm 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.
£38.80£46.56 Ex VATInc VAT£13.47£16.16 Per M2 Add to cart -
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.
£38.80£46.56 Ex VATInc VAT£13.47£16.16 Per M2 Add to cart -
140mm Kingspan Therma TP10 / TF70 / TW55 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pack of 2 (5.76m2)
All three models 140mm Kingspan Therma PIR Insulation Board:
- 140mm Thermapitch TP10
- 140mm Thermafloor TF70
- 140mm 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.
£139.15£166.98 Ex VATInc VAT£24.16£28.99 Per M2 Add to cart -
140mm Recticel Eurothane GP PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
140mm 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.
£39.56£47.47 Ex VATInc VAT£13.74£16.49 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.
£37.03£44.44 Ex VATInc VAT£12.86£15.43 Per m2 Add to cart -
150mm Celotex XR4150 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
150mm Celotex XR4150 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.
£39.81£47.77 Ex VATInc VAT£13.82£16.58 Per M2 Add to cart -
150mm Ecotherm Eco-Versal Rigid PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
The 150mm 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.
£39.81£47.77 Ex VATInc VAT£13.82£16.58 Per M2 Add to cart -
150mm Kingspan Therma TP10 / TF70 / TW55 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pack of 2 (5.76m2)
All three models 150mm Kingspan Therma PIR Insulation Board:
- 150mm Thermapitch TP10
- 150mm Thermafloor TF70
- 150mm 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.
£139.42£167.30 Ex VATInc VAT£24.20£29.04 Per M2 Add to cart -
150mm Recticel Eurothane GP PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
150mm 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.
£39.81£47.77 Ex VATInc VAT£13.82£16.58 Per M2 Add to cart -
165mm Celotex XR4165 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pack of 12
165mm XR4165 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.
£750.70£900.84 Ex VATInc VAT£21.72£26.06 Per M2 Add to cart -
200mm Celotex XR4200 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) Pack of 12
200mm XR4200 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.
£1,035.75£1,242.90 Ex VATInc VAT£29.97£35.96 Per M2 Add to cart -
25mm Celotex PIR Insulated Plasterboard 1200mm x 2400mm + 12.5mm P/B 2.88m2
25mm + 12.5mm Celotex PL4025 PIR Insulated Plasterboard is it is suitable for use in roof and internal wall lining applications. Celotex Insulated Plasterboard is a high performance, easy to install PIR insulation board with a paper facing, laminated to a piece of 12.5mm tapered edge plasterboard.
£28.33£34.00 Ex VATInc VAT£9.84£11.81 Per M2 Add to cart -
25mm Celotex TB4025 PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
25mm Celotex TB4025 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.
£10.29£12.35 Ex VATInc VAT£3.57£4.28 Per M2 Add to cart -
25mm Ecotherm Eco-Versal PIR Insulation Board 2400mm x 1200mm (8′ x 4′) 2.88m2
25mm 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.
£10.34£12.41 Ex VATInc VAT£3.59£4.31 Per M2 Add to cart
