Combination insulation

This form of insulation combines insulation between the rafters and an additional layer of insulation above or below the rafters.
thus rectifying the weak points of between-rafter insulation used on its own, and also permitting a slender roof structure.

Worth knowing ...

What are thermal bridges?

Individual, localised points in a structure where there is a high level of thermal transmittance in comparison with surrounding building components, e.g. rafters, window reveals and even corners of building components. Condensation may form at thermal bridges and cause damage to the building.
Thermal bridges can be reliably avoided by means of thermal insulation above or below the rafters.