Attic/Loft: Ceiling Level
This application ensures that heat generated within the living space does not pass into the attic and escape. This application is also one of the most important as up to 35% of heat loss from a house can occur here. To maximise the performance of insulation at ceiling level, a significant thickness is required. Ideally, this would be installed in a number of layers, covering the timber joists and reducing the opportunity for heat to escape through them (known as thermal bridging).
In houses with shallow joists, this might mean adding additional joists, or counter joists, if a floor is to be installed afterwards. Although this may mean additional effort at the time of installation, it offers a significant long term energy saving advantage. Premium or Comfort insulation rolls are suitable for this application, with Premium giving a superior performance and Comfort being the lower priced. For the purpose of these calculations, Comfort has been used.
The images below show some examples of this type of application:
Attic/Loft: Rafter Level
This is a common aproach when insulating dormer bungalows, storey and a half houses, vaulted or cathedral ceilings and attic conversions.
It is a particularly important element to insulate well as it can account for up to 35% of heat loss from a building and is typically the weakest line of thermal defense in all such house types.
To maximise the performance of insulation at ceiling level, a significant thickness is required. This may require installation using a number of layers. A 25-50mm ventilation gap may be required if the roof has a non-breathing or no membrane installed. In houses with shallow rafters, this might mean adding additional counter rafters to meet requirements. Although this may mean additional effort at the time of installation, it offers a significant long term energy saving advantage.
Premium insulation rolls are suitable for this application as they can be installed in the sloping rafter and stapled into place. For the purpose of these calculations, Premium has been used.
The images below show some examples of this type of application, Sheep Wool Insulation Premium Roll being installed between rafters.
