Cavity Wall Insulation Installation

By properly insulating cavity walls, you can guarantee you will save energy and cut costs off your heating bill.

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:

After 1920's
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.

Pre 1920's
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.

The first thing you need to find out is what sort of walls you have. If you can see the brickwork on the outside of the house, look at the pattern of the bricks.

Cavity Wall

If your home has cavity walls, the bricks will usually have an even pattern with all the bricks laid lengthways.

Solid Wall

If your home has solid walls, the bricks will have an alternating pattern, with some bricks laid across the wall so you can see the smaller ends from the outside.

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.

Many cavity walls can be insulated by injecting insulation material into the cavity from the outside.

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.

Costs and Savings

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.

You can check if your your home will be suitable for standard cavity wall insulation if it meets the following criteria:

You will then need us to carry out a survey. If it qualifies, we will then be able to insulate your walls using mineral wool, or polystyrene beads.