Under Rafters (Internal) Solutions

INSULATING A PITCHED ROOF BELOW & BETWEEN RAFTERS.

Insulating a pitched roof between and below the rafters is a very common roof insulation choice, particularly for retrofit and refurbishment projects.

This method of installing roof insulation allows you to maximise the headroom by using a thinner layer of insulation beneath the rafters, whilst achieving U-Values which will ensure you comply with Building Regulations and have a roof space or loft which is comfortable for its occupants.

The recommended roof insulation for this method of warm roof construction is shown below in the possible solutions.

SuperQuilt Under Rafters & Traditional Insulation Between Rafters

Breathable Membrane (Unventilated Cavity)

Non-Breathable Membrane (Ventilated Cavity)

Our internal pitched roof insulation solution is a quick and efficient method of insulating your pitched roof project.

Installing a layer of SuperQuilt internally removes the need for a vapour control layer, increases the overall thermal efficiency of the pitched roof and increases the internal space available due to its ultra-thin profile.

SuperQuilt can be used on its own or with traditional insulation such as PIR or mineral wool between the rafters.

Alternatively, multiple layers of SuperQuilt can be used to achieve your desired U-Value, for more information speak to our technical support team on 01909 726 025

Using SuperQuilt can significantly reduce the overall impact to head height, when compared to traditional insulation solution, saving you valuable money, time and space.

Once SuperQuilt has been taped and sealed on all overlaps and perimeter, it also works as a high performing VCL (vapour control layer).

Description (rafters at 400mm centres, Unventilated Cavity)U-Value
SuperQuilt 0.37
SuperQuilt and 75mm PIR (0.022 W/mK)0.18
SuperQuilt and 120mm Glasswool (0.035 W/mK)0.18
SuperQuilt and 100mm PIR (0.022 W/mK) or 90mm Phenolic (0.020 W/mK)0.16
SuperQuilt and 110mm PIR (0.022 W/mK) 0.15
SuperQuilt and 140mm PIR (0.022 W/mK)0.13
SuperQuilt and 190mm PIR (0.022 W/mK) 0.11
In accordance with BDA Kiwa Agrèment certification(W/m²K)
Description (rafters at 600mm centres, Unventilated Cavity)U-Value
SuperQuilt 0.37
SuperQuilt and 70mm PIR (0.022 W/mK)0.18
SuperQuilt and 100mm Glasswool (0.032 W/mK)0.18
SuperQuilt and 90mm PIR (0.022 W/mK) or 80mm Phenolic (0.020 W/mK)0.16
SuperQuilt and 100mm PIR (0.022 W/mK)0.15
SuperQuilt and 125mm PIR (0.022 W/mK)0.13
SuperQuilt and 165mm PIR (0.022 W/mK) or 150mm Phenolic (0.020 W/mK)0.11
In accordance with BDA Kiwa Agrèment certification(W/m²K)
Description (rafters at 400mm centres, Ventilated Cavity)U-Value
SuperQuilt 0.44
SuperQuilt and 85mm PIR (0.022 W/mK)0.18
SuperQuilt and 110mm PIR (0.022 W/mK) or 100mm Phenolic (0.020 W/mK)0.16
SuperQuilt and 120mm PIR (0.022 W/mK) or 110mm Phenolic (0.020 W/mK)0.15
SuperQuilt and 150mm PIR (0.022 W/mK) 0.13
SuperQuilt and 190mm PIR (0.022 W/mK) or 180mm Phenolic (0.020 W/mK)0.11
In accordance with BDA Kiwa Agrèment certification(W/m²K)
Description (rafters at 600mm centres, Ventilated Cavity)U-Value
SuperQuilt 0.44
SuperQuilt and 75mm PIR (0.022 W/mK)0.18
SuperQuilt and 100mm PIR (0.022 W/mK) or 90mm Phenolic (0.020 W/mK)0.16
SuperQuilt and 110mm PIR (0.022 W/mK) or 100mm Phenolic (0.020 W/mK)0.15
SuperQuilt and 135mm PIR (0.022 W/mK)0.13
In accordance with BDA Kiwa Agrèment certification(W/m²K)

2 Layers Of SuperQuilt Under Rafters & Insulated Plasterboard or Traditional Insulation Between Rafters

Our 2 layer internal pitched roof insulation solution is a quick and efficient method of insulating your pitched roof.

Properties with smaller rafter depth can be an issue when specifying traditional insulation like PIR & Mineral wool due to the high thickness of insulation required.

Recessing a layer of SuperQuilt between the rafters and a layer of SuperQuilt internally removes the need for a vapour control layer, increases the overall thermal efficiency of the pitched roof and increases the internal space available due to its ultra-thin profile.

SuperQuilt can be used on its own or in conjunction with an insulated plasterboard, giving you a hassle free installation, saving you valuable money, time and space.

For projects with larger rafters, traditional insulation like PIR and mineral Wool can be used between rafters, removing the need for an insulated plasterboard.

Once SuperQuilt has been taped and sealed on all overlaps and perimeter, it also works as a high performing VCL (vapour control layer).

Description (rafters at 400mm centres, Unventilated Cavity)U-Value
SuperQuilt (2 layers) 0.23
SuperQuilt (1 layer under) & SuperQuilt ( 1 layer recessed) with 38mm Insulated Plasterboard (PIR) (1.150 m²K/W)0.18
SuperQuilt (2 layers) and 25mm PIR (0.022 W/mK)0.18
SuperQuilt (2 layers under), SuperQuilt (1 layer recessed)0.16
SuperQuilt (2 layers) (under rafters) and 40mm PIR (0.022 W/mK)0.16
SuperQuilt (1 layer under) & SuperQuilt ( 1 layer recessed) with 53mm Insulated Plasterboard (PIR) (1.850 m²K/W)0.16
SuperQuilt (2 layers) (under rafters) and 50mm PIR (0.022 W/mK)0.15
SuperQuilt (1 layer under) & SuperQuilt ( 1 layer recessed) with 63mm Insulated Plasterboard (PIR) (2.300 m²K/W)0.15
SuperQuilt (2 layers) with 80mm Insulated Plasterboard (Phenolic) (3.560 m²K/W)0.13
SuperQuilt (2 layers) and 90mm PIR (0.022 W/mK)0.13
SuperQuilt (2 layers under) and 125mm PIR (0.022 W/mK)0.11
SuperQuilt (2 layers under), SuperQuilt (1 layer recessed) and 70mm PIR (0.022 W/mK)0.11
In accordance with BDA Kiwa Agrèment certification(W/m²K)
Description (rafters at 600mm centres, Unventilated Cavity)U-Value
SuperQuilt (2 layers) 0.22
SuperQuilt (2 layers) with 38mm Insulated Plasterboard (PIR) (1.150 m²K/W)0.18
SuperQuilt (2 layers) and 20mm PIR (0.022 W/mK)0.18
SuperQuilt (1 layer under) & SuperQuilt ( 1 layer recessed) with 53mm Insulated Plasterboard (PIR) (1.850 m²K/W)0.16
SuperQuilt (2 layers) (under rafters) and 40mm PIR (0.022 W/mK)0.16
SuperQuilt (1 layer under) & SuperQuilt ( 1 layer recessed) with 63mm Insulated Plasterboard (PIR) (2.300 m²K/W)0.15
SuperQuilt (2 layers) (under rafters) and 50mm PIR (0.022 W/mK)0.15
SuperQuilt (2 layers) with 70mm Insulated Plasterboard (Phenolic) (3.060 m²K/W)0.13
SuperQuilt (2 layers) and 75mm PIR (0.022 W/mK)0.13
SuperQuilt (2 layers under) and 110mm PIR (0.022 W/mK) or 100mm Phenolic (0.020)0.11
SuperQuilt (2 layers under), SuperQuilt (1 layer recessed) and 70mm PIR (0.022 W/mK) or 50mm Phenolic (0.020 W/mK)0.11
In accordance with BDA Kiwa Agrèment certification(W/m²K)
Description (rafters at 400mm centres, Ventilated Cavity)U-Value
SuperQuilt (1 layer under) & SuperQuilt (1 layer recessed)0.25
SuperQuilt (2 layers) and 25mm PIR (0.022 W/mK)0.18
SuperQuilt (2 layer under) with 53mm Insulated Plasterboard (Phenolic) (1.850 m²K/W)0.17
SuperQuilt (2 layers under) and 50mm PIR (0.022 W/mK) 0.16
SuperQuilt (1 layer under) & SuperQuilt (1 layer recessed) with 63mm Insulated Plasterboard (PIR) (2.300 m²K/W)0.16
SuperQuilt (2 layers under) and 60mm PIR (0.022 W/mK) 0.15
SuperQuilt (1 layer under) & SuperQuilt (1 layer recessed) with 80mm Insulated Plasterboard (Phenolic) (3.560 m²K/W)0.13
SuperQuilt (2 layers under) and 90mm PIR (0.022 W/mK)0.13
SuperQuilt (2 layers under) and 125mm PIR (0.022 W/mK)0.11
In accordance with BDA Kiwa Agrèment certification(W/m²K)
Description (rafters at 600mm centres, Ventilated Cavity)U-Value
SuperQuilt (2 layers) 0.24
SuperQuilt (2 layers) with 53mm Insulated Plasterboard (Phenolic) (1.850 m²K/W)0.18
SuperQuilt (2 layers) and 25mm PIR (0.022 W/mK)0.18
SuperQuilt (2 layers under) and 40mm PIR (0.022 W/mK) 0.16
SuperQuilt (1 layer under) & SuperQuilt (1 layer recessed) with 63mm Insulated Plasterboard (PIR) (2.300 m²K/W)0.16
SuperQuilt (2 layers under) and 50mm PIR (0.022 W/mK) 0.15
SuperQuilt (2 layers) with 80mm Insulated Plasterboard (Phenolic) (3.560 m²K/W)0.13
SuperQuilt (2 layers) and 80mm PIR (0.022 W/mK)0.13
SuperQuilt (2 layers under) and 120mm PIR (0.022 W/mK)0.11
In accordance with BDA Kiwa Agrèment certification(W/m²K)

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Product - SuperQuilt - See more

SuperQuilt is one of the UK’s leading multifoil insulations. This flexible, easy to install, multilayer insulation offers tremendous thermal benefits. The benefit of multifoil insulation is that it is suitable for a range of applications from roof insulation, floor insulation and wall insulation and due to the slim depth, you can save valuable space on your installation. The unique composition of the product effectively deals with all forms of energy transfer.

This product is suitable for roofs, walls, floors and offers the following major benefits –

  • Cost saving Solution
  • Effective 2 in 1 insulation and vapour control membrane
  • Reduces Construction Depth
  • Reduces Risk of Condensation
  • Non degradable maintaining thermal performance and product integrity

SuperQuilt has been independently tested and certified to the latest Industry Standards, including BDA Kiwa certificate of Agrément, Building Control Compliance (LABC registered detail) and NHBC Acceptance.