Cavity Wall Insulation

Save money and reduce your energy consumption with bespoke cavity wall insulation using spray foam, thermabead or fibre insulants.

Cavity Wall

What is Cavity Wall Insulation?

A cavity wall is a wall in your property that consists of a spacing in between another wall. For example, the exterior wall of your house may be a cavity wall which is two walls together separated by a gap. This is a relatively modern form of construction for residential and commercial properties. Traditionally walls were singular which cannot be insulated as well as a cavity wall. Cavity wall insulation simply fills this gap between the two walls allowing for a more insulated, soundproof and robust structure. Insulants such as spray foam can be used to fill your wall cavity.

Why do you Need Cavity Wall Insulation?

Insulating your cavity walls is important for every home, residential property and commercial property. There are many benefits and reasons that show the importance of insulating your cavity walls

1 Non-Insulation

Modern builds most likely have cavity walls and by not having them professionally insulated, you home will be unnecessarily losing heat, costing more for energy bills and you will experience a lot more discomfort than you should. Non-insulation can cause unwanted issues that can be easily resolved.

2 Added Value

If your home has insulated cavity walls, using an insulation that lasts the lifespan of a property, you are essentially adding value to your home. Due to the fact that insulated cavity walls have many benefits for homes, buildings and homeowners, by having them insulated, you can add value to your property.

3 Utilise Space

By having a cavity inbetween your external walls, you have a space that should be filled and can be filled for added benefits. By effectively utilising this space, your cavity, you can keep the warmth in your home, reduce sound pollution, save money on energy bills every month and a lot more benefits from it.

4 Prevent Mould

Cavity wall insulation can prevent the passing of water, toxins, pollutants and other nasty surprises. Due to the cell composition of certain insulations such as spray foam, your home or commercial property can prevent the growth of mould. Insulation keeps your property healthy for longer and requires less maintenance.

Do you have a Cavity Wall?

Unsure if your home has a cavity wall? Check out these factors below that can help you assess whether or not your home has a cavity wall.

Brick layout pattern is even.

If all properties of the wall are the same length.

Brickwork is more than 260mm thick.

Majority of homes built post-1920s have cavity walls.

If you can look down the cavity from the attic.

If the length of the bricks are similar.

If you have round holes in between bricks, where insulation has been blown in.

Narrow walls are usually solid not cavity walls.

What are the Benefits of Cavity Wall Insulation?

1 Save Money

Insulating your cavity walls provide one of the most (if not the most) effective means of conserving energy and, therefore, helping you save money. Up to 33% of heat loss occurs through your walls, which is, arguably, the most wasteful area in terms of heat loss for your home. By installing spray foam insulation will dramatically reduce that figure and, in turn, begin to cut your own energy bills down by up to 35% every month.

2 Environmentally Friendly

Using spray foam insulation for your cavity walls is one of the most eco-friendly insulants you can use to reduce your energy consumption and lower your energy bills. Because your home will be better insulated, reducing the amount of heat loss through your walls, your reliance on heating and cooling will reduce, therefore, you will lower the amount of carbon emissions released every year. The UK government is pushing homeowners to install more eco-friendly insulation, such as spray foam, and are even providing funding for it. (To learn more about the governments Green Homes Grants scheme, you can check it out here)

3 Enhanced Quality of Life

By insulating the cavities in your walls, you are essentially slowing down the movement of heat through your walls, keeping it inside and keeping your home warm and comfortable. It is important to maintain a good indoor temperature throughout the cold winter months and the warm summer months. Cavity wall insulation is both a solution for winter and summer, enhancing your quality of life every day.

4 Ease of Installation

Insulation can be messy, invasive and disturbing to install, creating unwanted havoc in your household. However, with our spray foam insulation, it can be easily applied into your cavity walls with minimal invasiveness and little to no disruption. Our professionals simply spray the insulation through a hole directly into your cavity walls, filling them up with quality insulation. It is a quick and easy task when using our spray foam insulants.

5 Soundproofing

Do you live in a noisy area or experience unwanted noises throughout the day? Cavity wall insulation can fix just that, when using spray foam. Spray foam has high-performing acoustic properties that absorb sound and provide you with the peace you desire in your own home. There’s no reason why you shouldn’t be able to relax and find peace within you own home, so cancel out those unwanted noises with our insulation products.

6 Structural Integrity

By insulating your cavity walls with one of our recommend insulants, you add a great deal of structural integrity to your property. Filling your homes cavity can reinforce your properties walls, creating a firm and sturdy effect. If your property is situated in areas that are subject to harsh weathers, then insulating your cavity walls can be a great solution for you.

What are the Best Products for Insulating your Cavity Wall?

There are a variety of products you can use to insulate the cavity between your external walls. Our professionals recommend three main insulants that can do the job, each with their own capabilities.

Spray Foam Insulation

Our experts most recommend insulant for filling your cavity wall would be spray foam insulation. This product is an advanced solution and, as one of the earliest spray foam installers, it’s advanced technology can perform a non-invasive insulation of your cavity area. Foam insulant also has one of the most superior thermal properties (mainly closed-cell foam) and can help you save up to 35% on your monthly energy bills. Additionally, open-cell spray foam handles sound absorption very well and is one of the best insulants for handling noise pollution on the market today.

Spray Foam

EPS Beading Insulation

Secondly, EPS Beading can provide insulation to your cavity walls at a high level. This insulation is strictly applicable to cavity walls and is more traditional than spray foam, yet still an advanced and effective solution. EPS Beading involves the process of injecting beads into the cavity of your wall, beads which last the lifespan of your property. Importantly, if you use an EPS Beading solution, there is no need to install the traditional cavity boards to fit the insulant, therefore saving time and money.

Fibre Insulation

Lastly, our least recommended method, yet still an applicable form of cavity wall insulation, using fibre insulation. This is one of the most traditional forms of insulation used for cavity walls and it consists of an entirely dry insulant. The benefits of using fibre insulation for cavity walls is that it requires simple planning, it can be quick to insulate with the correct measures and it is one of the cheaper more cost-effective means of insulation. Additionally, fibre insulation is more eco-friendly than non-recommended traditional insulation such as copper cables.

Fibre Insulation
where to get cavity wall insulation supplier

Where To Get The Best Closed Cell Foam Insulation Services

If you’re looking to invest in closed cell foam insulation, get in touch with Eco Spray Foam today. We are Icynene-accredited quality insulation providers who offer bespoke insulation services across the entire United Kingdom.

For over twenty years, Eco Spray Foam has been delivering premium quality products and expert services. We provide the latest technological insulation solutions for modern-day applications and are certified users of the Icynene spray foam product, which is one of the newest insulating technologies on the market today.

To find out more about our products and services, and to get a free insulation survey for your residential or commercial property, get in touch with us by calling 0203 411 5188 or by filling out our online contact form at

Our friendly team of experts here at Eco Spray Foam are ready to provide advice and guidance on the best insulation solutions for your home.


  • What is a Cavity Wall?

  • A cavity wall is when your external walls of your property is constructed of two masonry walls, which leaves a gap, know as the cavity, in between the two walls. Cavity walls are very common in homes and is a relatively modern form of construction in residential properties.

  • Is my House Suitable for Cavity Wall Insulation?

  • Our insulation experts can undergo a survey of your property to assess the suitability for cavity wall insulation, providing professional advice on the next steps to take in order to carry out the insulation installation.

  • How can I tell if my Walls are Full??

  • Our experts use an injection assessment pattern that monitors injection holes to see that the insulation material meets and passes each hole until it is full. Each system also has a defined pattern of holes that will need to be tested and verified, which, consequently, results in a complete fill.

  • How Long will Cavity Wall Insulation Last?

  • According to the BBA (British Board of Agreement), cavity wall insulation will last for the life of the building. When you use a spray foam insulant, we also provide a 25-year insurance guarantee when you use our spray foam insulation.

  • Will my Home be Warmer in the Winters?

  • Yes, by installing cavity wall insulation, you will reduce the amount of heat exiting your walls (which can be up to 33% of your properties heat), therefore, keeping the warmth in your home. Additionally, your household will retain its temperature for longer, as your wall’s thermal resistance would be increased.

  • Do I need to do anything before the Installation?

  • When installing insulation via an injection method, there may be some vibration of the walls, so we recommend removing any ornaments, frames or other delicate furniture/accessories you may wish to protect. All walls will undergo an assessment/surveying process to assess what will be required to install the insulation.

  • How is the Cavity Wall Insulation Installed?

  • Our experts inject cavity wall insulation directly into the cavity, for example, using spray foam, we will inject it into the wall’s cavity via an external hole in the mortar joint. Holes are typically small, between 22-25mm diameter and are fixed post-injection. Each hole made will follow an injection, starting from the very bottom hole.

Other Types of Wall Insulation

View some of our residential and commercial wall insulation services.

Residential Wall Insulation
Commercial Wall Insulation
EPS Beading Wall Insulation