Cavity Wall Insulation is used to reduce heat loss through a cavity wall by filling the air space with a porous material. This immobilises the air within the cavity (air is still the actual insulator), preventing convection, and can substantially reduce space heating costs.
Cavity wall insulation is normally applied from the outside. A trained technician drills small holes in the external wall using a pattern specified within the industry technical standards.
The cavity wall insulation material is then pumped into the holes using a blowing machine; this has an automatic cut-out (like a petrol pump) that actuates when the wall area is full. The holes are then made good to match the existing finish as closely as possible. Once installed, the cavity wall insulation requires no maintenance and will last for the lifetime of the building.