Cavity Wall Insulation Installation
About a third of all the heat lost in uninsulated properties escapes through the walls
As a rule, houses built from the 1990s onwards generally had wall insulation to keep the heat in, but if your house is older than that, it may not have any wall insulation at all.
Houses in the UK mostly are built with either solid walls or cavity walls:
If your house was built after the 1920s, it is likely to have cavity walls. A cavity wall is made up of two walls with a gap in between, known as the cavity; the outer leaf is usually made of brick, and the inner layer of brick or concrete block.
If your house was built pre-1920, it is more likely to have solid walls. A solid wall has no cavity; each wall is just a single block solid wall, usually made of brick or stone.
Working out your wall type
If the brickwork has been covered by some cladding or rendering, you can still tell by measuring the width of the wall. You can do this by looking at a window or door on one of your external walls.
If a brick wall is more than 260mm thick then it probably has a cavity a narrower wall is probably solid. Stone walls may be a bit thicker still but are usually solid, for example an old cottage made on limestone.
Some houses have a different type of wall structure altogether. If your house is a steel-frame or timber-framed building, or is made from pre-fabricated concrete, then you will need to ask us to advise first.
Cavity wall insulation explained
We generally will drill holes in the outside walls, inject insulation through the holes and then seal them with cement. The insulation material is usually either mineral wool or polystyrene beads, but polyurethane foam may sometimes be used instead.
To insulate your cavity walls, we will drills small holes around 22mm in size at intervals of around 1m in the outside wall of your home. We then will blow insulation into the cavity using our special equipment. Once all the insulation is in, we will fill in the holes in the brickwork so you barely notice them.
Typical installation costs of cavity wall insulation vary depending on the size of your home. But whether you live in a large detached house or small flat, you should be able to make back the installation cost in less than five years through cheaper energy bills.
If you qualify for our grant this will cost you nothing.