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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.
£1,429.07£1,714.88 Ex VATInc VAT£23.63£28.36 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.
£1,263.40£1,516.08 Ex VATInc VAT£24.37£29.24 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.
£1,115.19£1,338.23 Ex VATInc VAT£25.81£30.97 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.
£1,113.58£1,336.30 Ex VATInc VAT£27.62£33.14 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.
£1,017.92£1,221.50 Ex VATInc VAT£29.45£35.34 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.
£980.44£1,176.53 Ex VATInc VAT£30.95£37.14 Per M2 Add to cart
Pitched Roof Insulation K118
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.
