Over Rafters (External) Solutions

INSULATING A PITCHED ROOF OVER AND BETWEEN RAFTERS.

Insulating a pitched roof over and between the rafters is a common method chosen for re-roofing existing buildings, extensions and new builds as it provides superior thermal performance for the building. Insulating the roof above the rafters is known as warm roof insulation as the rafters are brought into the insulated envelope of the building.

This over-rafter insulation method also reduces thermal bridging, giving an airtight continuous layer of high-performance insulation and results in a well-insulated attic space.

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

BreatherQuilt Over Rafters (Draped Detail) & Traditional Insulation Between Rafters

Our over rafter insulation solution is perfect for any type of application where there is access over and between the rafters.

BreatherQuilt removes the need for a separate breather membrane as it built into the product.

Using our draped installation detail keeps the overall roof profile height down to a minimum, by allowing the BreatherQuilt to expand between the rafters.

BreatherQuilt can be used on its own or in conjunction with traditional insulation like PIR or Mineral Wool between the rafters.

BreatherQuilt gives you a hassle free installation, saving you valuable money, time and space.

The low vapour resistance of BreatherQuilt allows the rafters to breath and its W1 rating keeps the external elements out.

Description (rafters at 400mm centres)U-Value
BreatherQuilt0.56
BreatherQuilt and 120mm PIR (0.022 W/mK)0.18
BreatherQuilt and 170mm Mineral Wool (0.035 W/mK)0.18
BreatherQuilt and 140mm PIR (0.022 W/mK) or 130mm Phenolic (0.020 W/mK)0.16
BreatherQuilt and 150mm PIR (0.022 W/mK) or 140mm Phenolic (0.020 W/mK)0.15
BreatherQuilt and 190mm PIR (0.022 W/mK)0.13
BreatherQuilt and 225mm PIR (0.022 W/mK) or 215mm Phenolic (0.020 W/mK)0.11
In accordance with BDA Kiwa Agrèment certification(W/m²K)
Description (rafters at 600mm centres)U-Value
BreatherQuilt0.56
BreatherQuilt and 110mm PIR (0.022 W/mK)0.18
BreatherQuilt and 150mm Mineral Wool (0.035 W/mK)0.18
BreatherQuilt and 125mm PIR (0.022 W/mK) or 115mm Phenolic (0.020 W/mK)0.16
BreatherQuilt and 135mm PIR (0.022 W/mK) or 125mm Phenolic (0.020 W/mK)0.15
BreatherQuilt and 165mm PIR (0.022 W/mK)0.13
BreatherQuilt and 200mm PIR (0.022 W/mK) or 190mm Phenolic (0.020 W/mK)0.11
In accordance with BDA Kiwa Agrèment certification(W/m²K)

BreatherQuilt Over Rafters (Taut Detail) & Traditional Insulation Between Rafters

For projects where the overall profile height of the roof is not an issue or the rafters have a reduced depth, using out taut installation detail with a counter batten above the BreatherQuilt offers a great solution.

Maximising the space between the rafters for additional insulation to be installed.

You get the same benefits form BreatherQuilt whichever installation option you choose.

Description (rafters at 400mm centres)U-Value
BreatherQuilt0.54
BreatherQuilt and 120mm PIR (0.022 W/mK)0.18
BreatherQuilt and 170mm Mineral Wool (0.035 W/mK)0.18
BreatherQuilt and 140mm PIR (0.022 W/mK) or 130mm Phenolic (0.020 W/mK)0.16
BreatherQuilt and 150mm PIR (0.022 W/mK) or 145mm Phenolic (0.020 W/mK)0.15
BreatherQuilt and 185mm PIR (0.022 W/mK)0.13
BreatherQuilt and 230mm PIR (0.022 W/mK) or 215mm Phenolic (0.020 W/mK)0.11
In accordance with BDA Kiwa Agrèment certification(W/m²K)
Description (rafters at 600mm centres)U-Value
BreatherQuilt0.58
BreatherQuilt and 110mm PIR (0.022 W/mK)0.18
BreatherQuilt and 150mm Mineral Wool (0.035 W/mK)0.18
BreatherQuilt and 125mm PIR (0.022 W/mK) or 115mm Phenolic (0.020 W/mK)0.16
BreatherQuilt and 135mm PIR (0.022 W/mK) or 125mm Phenolic (0.020 W/mK)0.15
BreatherQuilt and 165mm PIR (0.022 W/mK)0.13
BreatherQuilt and 205mm PIR (0.022 W/mK) or 190mm Phenolic (0.020 W/mK)0.11
In accordance with BDA Kiwa Agrèment certification(W/m²K)

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YBS Insulation products are manufactured to the highest quality and certified to industry standards.

YBS Insulation Product Information

Product - BreatherQuilt - See more

YBS BreatherQuilt is a high performing Agrément Certified insulating multi-foil offering both thermal properties, along with a highly effective breathable membrane which is both water resistant and vapour permeable.

Designed to replace the need for a stand alone breather membrane, whilst offering a high level of thermal performance, the unique layer composition of BreatherQuilt effectively deals with condensation and all forms of energy transfer. Flexible and easy to install this high quality insulation provides a sustainable approach to thermal and breathable insulation. Suitable for use in pitched roofs, BreatherQuilt now includes a built in double-sided tape for ease of installation.

This product is suitable for pitched roofs and offers the following major benefits –

  • Dual purpose 2-in-1 insulating and breathable roofing membrane
  • Removes the risk of condensation
  • Effectively reflects heat back into the room, whilst allowing moisture to pass through
  • Low vapour resistant breather membrane (LR)
  • Waterproof outer membrane with Class W1, can be left exposed for up to four weeks
  • Zero fibres removes the need for PPE
  • Unique overlapping method, totally removes the risk of thermal bridging
  • Now includes built-in easy peel double sided tape for ease of installation

BreatherQuilt has been independently tested and certified to the latest Industry Standards, including BDA Kiwa certificate of Agrément and is accepted by NHBC.