If your property was built after 1930 then it is likely to have Cavity Walls. A Cavity Wall is where the external wall of a house is constructed of two masonry (brick or block) walls, with a cavity of at least 40mm between. A property with Cavity Walls can usually be identified by its brick pattern which is known as ‘stretcher bond’, where all the bricks are laid lengthways. Another way to identify a cavity wall is by the wall thickness, this is usually over 270mm thick.

Cavity Wall Insulation is installed by drilling a series of holes on the mortar joints of the external wall and injecting a bonded polystyrene bead. Once the cavity is full, the holes are made good and colour matched as closely as possible to the original mortar. All installs are supported by a 20-year insurance backed guarantee.

A cavity wall is one of the two walls needed to have 'cavity walls'. Cavity walls are walls that are built next to each other with a small gap between them, typically about 50mm.

Filling cavity walls with insulation will raise your energy performance certificate's band, save you money on your heating bill (up to £150 per year) and will keep you warmer during those cold months.