Cavity wall insulation – whats it all about?
The external walls of a house are actually made of two walls, an inner wall and an outer wall, with a gap of at least 50mm between them. The cavity was originally designed to stop homes getting damp and if your home was built from 1920 onwards, it’s very likely that the external walls are made of two layers with a small gap or ‘cavity’ between them, hence the name Cavity Wall. Insulating your cavity walls means filling that gap, there are very good reasons for this.
