What Type of Insulation is Best for Cavity Walls?

Cavity walls are an extremely common building structure for homes across England. Properties that were built after the 1920s are likely to have cavities in between their external walls. The importance of a home that has cavity walls is the fact that they can be insulated to help save homeowners money on energy bills and to create a high standard of living. Unless your home was built in the last 20 years, you are likely to have cavity walls that are empty, newer homes that are constructed typically have their cavities filled, they can be filled with insulants such as liquid cavity wall insulation.

The importance of cavity wall insulation is not to be overlooked; did you know that up to one-third of heat loss occurs through the walls? This mean that, you could save an estimate of £160 per year only in heating bills. Moreover, according to Energy Saving Trust, you could see a complete ROI on your cavity wall insulation investment within less than 5 years. When insulating your cavity walls, you have a variety of insulants to choose from, such as liquid cavity wall insulation, EPS beads or blown-in mineral wool.

How can you check if you have a cavity wall?

Although age is an indication to whether your home has cavity walls or not, sometimes you may not know the actual age of your property. Therefore, you can inspect your external walls for other features that will help you determine if they have a cavity. For example, if the lengths of the bricks are all the same size and no placed end-on, then it is likely a cavity wall. Other notifiers can be small 1-inch holes at regular intervals, these holes may indicate when cavity wall insulation has previously taken place, you may be able to see some faint marks. Additionally, you can check your loft, sometimes the external wall cavities have insulation spill visible from your loft (this should b checked and removed if so), therefore it will indicate if your home’s walls have a cavity.

If you are still unsure if you have a cavity wall, then you can ask a registered installer to drill a small hole in the wall in order to inspect, known as “borescope inspection” or you can even check with the building control department of your local authority, they should hold records on your walls if they have been previously insulated.

Cavity Wall Insulation Types

Acknowledging if you have a cavity wall or a solid wall is step one, next, you have the option to decide on which type of cavity wall insulation you can have installed. Different types will have various pros and cons but with the same overriding objectives that benefit you and your home. The main types of cavity wall insulation are:

  • Blown-in Mineral Wool
  • EPS Beads
  • Liquid Cavity Wall Insulation

Blown-in Mineral Wool Insulation

This type of cavity wall insulation is fairly common and similar to loft blanket insulation, but instead of being provided in rolls, it is broken up and blown in. Mineral wool insulation for cavities is typically inexpensive compared to other forms but also has some weaknesses. The insulant will settle over time which will cause air pockets at the top of the walls. This will reduce your energy saving ability as more heat will escape through your external walls. Additionally, mineral wool must be kept dry otherwise it will lose its insulation ability.

EPS Beads Insulation

Insulating cavity walls with EPS beads provides a long-lasting and innovative insulation solution. The beads are very efficient at trapping heat and covering all gaps in the cavity for an effective insulation. The ease of their blown-in nature also means that you do not need to use cavity boards to fit the insulation. However, some drawbacks are the fact that loose granules can escape through airbricks and, if in future, you need any work done to your walls that involves drilling or cutting, the eps beads can quickly pour out.

Liquid Cavity Wall Insulation

Liquid cavity wall insulation, also known as spray foam insulation, is a highly innovative insulant sprayed injected into your cavity walls and sprayed in from a liquid state. Foam insulation offers the highest thermal properties and requires experts to best install it, although it is quickly and easily installed. Icynene spray foam is a high-quality foam insulation manufacturer and provides long-lasting insulation solutions. Opting in for this liquid foam insulation, you will receive benefits beyond thermal insulation and saving money. This insulant can also provide soundproofing and has many environmentally friendly benefits, cutting you co2 emissions every year and reducing your carbon footprint. Due to the superior thermal capabilities, you will best see a ROI when opting in for this liquid cavity wall insulation type.

Finding the right installer

At Eco Spray Foam Systems, we are approved installers with the British Board of Agreement (BBA), the Cavity Insulation Guarantee Agency (CIGA) and the National Insulation Association (NIA). We are also on the board of the NIA, reflecting our expertise in the insulation field. As a certified installer of cavity wall insulation, not only do we uphold a code of practice and are fully qualified, but we can also provide a 25-year guarantee on spray foam insulation.