When rafter or stud depth needs to be kept to a minimum during a project to save on internal space, it might be it difficult to achieve the required U-Value. It is possible to overcome the affects of a lack of space to house the insulation by choosing the right combination of materials before your project begins.
A multi-foil insulation layer such as Superquilt or Superfoil can add significant thermal performance to a property when combined with the air-tight spray foam insulation.
Multi-foil insulation can be installed above or below the roof rafter, spray foam insulation can then be applied directly to the foil membrane to create a seamless thermal layer.
The reflecting qualities of multi-foil insulation truly help to deflect solar gain away from a property during the summer whilst retaining the heat from within the property in cold winter months. As a standalone insulation system, multi-foils such as Superquilt or Superfoil, do not provide enough thermal performance to satisfy U-Value requirements and should always be used in conjunction with a foam insulation.
You may choose to install a multi-foil insulation above the roof rafter to replace the requirements for a roofing membrane as it offers good water vapour resistance. Alternatively spray foam insulation could be installed between the roof rafters directly to a breathable membrane with a multi-foil insulation fit under the rafter.
For more advice on choosing the optimum insulation solution for your project, contact our technical team today.