Roof insulation is insulation materials that are installed into pitched roofs or flat roofs to improve the thermal conductivity of the residential or commercial building. The materials are frequently made up of high-performance, rigid polyisocyanurate (PIR) featuring foil facings on both sides or mineral wool and other forms of insulation depending on the method of installation applied. On our website, you will find a variety of roof insulation products from the top brands, but at trade prices.

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Kingspan OPTIM-R Roofing System

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Kingspan Thermataper TT44 Tapered Insulation (1.2m x 1.2m)

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Kingspan Thermataper TT46 Tapered Insulation (1.2m x 1.2m)

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Kingspan Thermataper TT47 Tapered Insulation (1.2m x 1.2m)

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100mm Recticel GP Insulation Boards (1200x2400mm)

£36.20 ex VAT

Celotex 100mm PIR Insulation Board – GA4100 (2.4m x 1.2m)

£36.20 ex VAT

Celotex 37.5mm Insulated Plasterboard (1200x2400mm) – PL4025

£34.95 ex VAT

Kingspan Kooltherm K7 100mm Pitched Roof Board

£296.89 ex VAT

Knauf 100mm Loft Roll 44 – Combi Cut (13.89m2 Roll)

£24.10 ex VAT

Knauf Soundshield Plus Panel 12.5mm (2400mm x 1200mm) Tapered Edge (2.88m2)

£11.64 ex VAT

Knauf Wallboard Plasterboard 12.5mm (2400mm x 1200mm) (2.88m2) Tapered Edge

£6.80 ex VAT

ROCKWOOL Flexi – 1200 x 400 x 100mm – (2.88m2)

£719.77 ex VAT

ROCKWOOL Flexi Slab – 1200 x 600 x 100mm – (4.32m2)

£1,000.00 ex VAT

Rockwool RWA45 100mm Acoustic Insulation Slab

£19.61 ex VAT

100mm Kingspan Thermaroof TR24 PIR Flat Roof Insulation Board (1200 x 600mm)

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120mm Celotex Insulation Board – XR4120 (2.4m x 1.2m)

£46.50 ex VAT

How is roof insulation installed?

Roof insulation depends on the type of roof that is being insulation such as a flat or pitched roof. The method of insulation required will differ depending on the type. Another factor to consider when insulating a flat roof is whether the property has a warm or cold roof structure.
Installing Flat Roof Insulation
Flat roofs are insulated by externally layering insulation materials on top of the roof providing it is a warm roof. Plywood and vapour check is fixed to the roof and then insulation is applied and tightly butted together and secured using foil tape. Other methods then follow such as more battens, plywood, vapour check (weatherproof sheet), and drip trims etc. This method means no mess or changes need to be made to your home internally and will be an easier form of application for the property owner.

Cold Roof vs Warm Roof

  • Cold roof is when the insulation is fitted in between the rafters of the roof and timber deck is applied over the top along with weatherproof coverings. This method is referred to as cold roof as cold spots can occur at the rafters causing thermal bridging.

Using a cold roof technique can means having to replace boards on the roofs surface.

  • Warm roof is when timber deck is applied directly to the rafters and then insulation is layered on top. This method is referred to as warm roof as due to application of insulation it prevents thermal bridging.

Overall cold roof is more work, takes longer and does not provide great thermal conductivity. Warm roof is a quick and easy application that provides great thermal conductivity. Warm roof is a method used by most building professionals.

Installing Pitched Roof Insulation
Pitched roofs are insulated internally. This method involves the vertical spaces in between the rafters in the roof being measured, and then measuring and cutting the chosen insulation boards to fit, and then fasten into the spaces in the rafters. In some cases, the spaces in between the rafters can differ, so ensure each board is cut and measured as you go. The length and width of the rafters are then measured, and another layer of insulation board is then applied horizontally across top of the existing insulation boards and fixed to the rafters. Make sure your boards and measured correctly and will cater for needs such as a sloping roofs and uneven rafters.

  • Loft insulation can also be installed to provide extra insulation.
  • If you’re using your roof / loft as a living space ensure all sides are insulated including floor, walls, and roof.
  • Always make sure the correct materials are applied around windows, doors, and vents to avoid thermal bridging.

Why do I need roof insulation?

Heat rises, roof insulation will prevent heat from escaping through the ceiling and improve the energy efficiency of your home as well as saving you money on energy bills. Up to 30% of heat can be lost through roofs that do not have the required insulation installed properly. Roof insulation applied correctly can mean cooler summers and hotter winters, making a more comfortable living or working space at more controlled temperatures. specific insulation materials designed for certain requirements can also prevent mould, rot or damp, can add an acoustic advantage and add extra protection with the prevention of fire. Roof insulation can have a lifespan as long as the building itself.
When installing roof insulation take safety measures to ensure insulation is fitted correctly around electrical sockets, wires, and ventilation spaces, or the correct procedures are put into place to remove these components.
Always consult a building professional when insulating your roof to prevent the wrong insulation from being installed and the possibility of damaging your property.
Some roofs are harder to reach and not accessible in which case a specialist can be called in with the correct tools to insulate the roof.

Building Regulations:
Relevant building regulations will need to be met when insulation your roof. Installers will usually arrange this however it is your responsibility to assure you are complying with regulations.
The Roof should achieve a U-value of no more than 0.20 W/m2K, if possible. The U-value is calculated by measuring how quickly heat will travel through the roof.

IKO insulation boards are rigid boards of high quality polyisocyanurate (PIR) foam with a layer of clad on both sides and an aluminium foil layer on each side of the board. It is a lightweight product and is easy to handle, install and can be easily cut with a hand saw or Stanley blade. This product is a multi-purpose board that can be used in walls, floors, pitched roofs, and flat roofs. It is a great product for roof insulation as it is moisture-proof and will prevent rot, damp, and mould. The size is 1200mm by 2400mm and comes in a variety of widths ranging from 25mm to 150mm. This product provides an excellent thermal conductivity of 0.022W.mK.

The Kingspan Thermaroof TR27 has a high-performance, fibre free, rigid thermoset core with coated glass tissue facings on each side which is specifically designed for flat roof insulation. It is a durable product that is easy to install. The TR27 is resistant to solvent, rodents, and fungi. Please note this product should be pair with waterproofing insulation materials. This product size is 1200mm by 1200mm and comes in widths ranging from 25mm to 150mm. The flat roof insulation board has a thermal conductivity between 0.024W.mK and 0.027W.mK depending on the size needed.

Kingspan Kooltherm K107 is a premium performance insulation designed for pitched roofs. This product has a fibre-free rigid thermoset phenolic core and has a layer of aluminum foil on each side. The K107 is a great product for insulating warm roof spaces in ventilated or unventilated pitched roofs and can be used under tiles and slates. This product is 1200mm by 2400mm and comes in a variety of widths from 25mm to 120mm. the pitched roof board has an excellent thermal conductivity of 0.018W.mK.
Other products can be used for flat and pitched roof insulation. These products include insulated plasterboard, glass mineral wool slabs, mineral wool rolls, and standard PIR boards.