No cavity wall

Cavity Wall: How To Insulate Walls Without Cavity?

What Is Cavity Wall?

Cavity wall refers to a double wall separated by a hollow space, known as 'Cavity'. The outer layer wall is commonly constructed of brickwork, whereas the inner layer is built from either bricks or concrete. Brickwork and concrete, are highly absorbent. Thus when it rains, humidity is absorbed into the house. Similarly, heat from within the home is lost.

insulation with cavity

Do I Have Cavity Wall?

It is advisable to contact a surveyor to accurately confirm if your home has cavity wall or not. However, for those that would like to save some change, there are a few ways in which you can identify whether you have cavity wall or not. If you don't have cavity walls, click here to find out how to insulate your home.

The thickness of your external walls 

Another way in which you can check if you have cavity wall is by measuring the thickness of your external walls. Due to the cavity (empty space) between the external and internal wall, cavity walls will be thicker than a usual solid wall.

To measure the thickness, open up window or front/back door and measure from the wall. If the external wall has a thickness that is less than 30cm there isn't any cavity wall. But, any more than 30 cm there is a cavity wall.

The pattern of the bricks 

Did you know that the pattern of a brick wall can tell you a story about your home? There are three typical brickworks in the UK; stretch bond, English bond and Flemish bond.

Cavity Wall Stretcher Bond

No cavity wall - English bond

No cavity wall - Flemish bond

Age of your home

From the age of your property, you can suggest whether or not your home has been built with a cavity wall.

Homes Built in the period of:

Before 1932                Unlikely to have cavity walls

1932 - 1982                Highly likely

After 1982                  Almost certain

There are cases where improvements have been made to the property (e.g a kitchen extension), where cavity walls have been built.

Alternative Insulation Options

If you are certain that your property doesn't have cavity walls, but you're still concerned about the warmth of your home. Don't be disheartened. There are still alternative insulation methods that can be just as effective - in some cases even more.

External Wall Insulation

As it states in the name external wall insulation (EWI) is an insulation method that consists of fixing layers of insulation materials to the outside walls. This is then followed by a reinforcement, which helps secure the insulation into place. Then finalised with a unique type of render. Render comes in various textures to suit the build and appearance of your property. EWI can come in the form of EPS. What EPS is, is expanded polystyrene. This uses polystyrene as one of the fixing layers. EPS comes in a variety of thicknesses: 20mm, 50mm, 70mm, 90mm, and 100mm.



EWI is a very difficult job. The complex construction makes it a nightmare for installers. Also, polystyrene foam has a weak structure, making it prone to falling apart.

Loft Insulation

It may seem a bit off topic, but loft insulation is, in fact, a great alternative for cavity wall insulation. People are made to believe that wall insulation is the only way to reduce heat loss which is false.


However, almost 50% of the heat is lost through the roof. This makes spray foam loft insulation a great replacement, creating an air barrier in your loft, trapping the cool air in and cold air out. Essentially, saving you up to 50% on your energy bills.

ProPerla Masonry Creme Coating

ProPerla masonry creme coating is applied to the exterior wall. This method of insulation has been developed over the past 20 years with groundbreaking technology, making it a superior external wall insulator. ProPerla is an ideal alternative for those without cavity due to it penetrating deep into the surface, creating an effective insulation barrier. Moreover, as the creme is so absorbable it makes the surface (whether brick or concrete) look as if nothing has touched it. Therefore acting as an invisible barrier.


ProPerla: High Performance

ProPerla masonry creme coating has been proven to be an outstanding product, being tested and certified to standards. This comes as no surprise with its amazing ability to reduce water absorption by more than 95%. You may not think this is important. However, once the pores of the wall collect moistures, the heat from within your property is transferred.

To learn more about ProPerla and the step-by-step guide of how it is installed click here.

This waterproofing phenomenal is the ideal alternative to cavity wall insulation. The application is simple and with its rapid setting time, you will notice the improvement immediately.