Guide to Cavity Wall Insulation: Increase the Energy Efficiency of Your Home

by | Nov 25, 2021 | Design

Heating and cooling make up for the majority of a home’s annual total energy usage. Poor insulation can make your home less comfortable, be the cause of major air leakage, and make your home an unhealthy living environment. If your home features quality siding and roofing that’s not insulated properly, your house will be protected from the elements, but you still won’t be as comfortable as possible. 

Warm air always flows to cooler areas, and insulation helps prevent this airflow through roofs, ceilings and walls. In other words, it prevents heat from escaping your home in the winter, and it prevents it from entering your home in the summer.

There are different types of insulation materials, all of which have different properties. The two most popular ones are cavity wall insulation and glass wool insulation, used for houses and buildings, respectively.

Cavity Wall Insulation

This is one of the most cost-effective insulation solutions available. It’s easy to install, reduces heat loss, making your home more energy-efficient in the process. Most older homes that are built after the 20s will probably come with cavity walls. So unless the home was built in the last two decades, it will probably be hallow. Filling the cavity wall with quality Kingspan panels UK insulation stores sell will lead to great energy savings. Cavity walls are empty on the inside, and you can fill them up with insulating materials through drilled holes. Cavity wall insulation is super easy to install, and it doesn’t leave a mess.

Glass Wool Insulation

This type of insulation is made from a combination of sand and recycled glass. It’s commonly known as fibreglass wool, and it’s used in buildings. It’s made by spinning glass into a fibrous material which is later packed in panels and blankets. It’s manufactured by many industry-leading manufacturers around the UK. You can purchase glass wool insulation in addition to the Kingspan panels UK insulation, which is bound to last for a long time.

Does Your Home Have Cavity Walls?

Figure out when your home was built. This can be done quickly by checking your mortgage survey. If the home was built after the 1920s, it probably features solid wall or cavity wall construction. Next, check for exposed or visible brickwork on the outside. This will probably tell you whether cavity wall construction was used. If the bricks are different in length, and some of them are placed “end on”, it means cavity wall construction was used in the building process. Regardless, a quality installer will assess your home and confirm whether you need cavity wall insulation or not. 

If your home is less than 30 years old, then it probably has its wall cavities insulation. You can check your Energy Performance Certificate to figure out whether insulation was installed. Alternatively, you can check with your local authorities, as they will probably have a file from the local building control department. If that doesn’t solve your dilemma, you can ask an insulation installer to drill a small home into your walls to see whether the cavity wall is empty or insulated. This process is known as borescope inspection.

Is Cavity Insulation Suitable for Your Home?

Once you figure out if your home has cavity walls, there are a few important points to consider. You should only use cavity wall insulation if:

  • Your home features unfilled cavity walls made of brick;
  • The cavity is at least 5cm wide and is clear of rubble;
  • The masonry and brickwork are in decent condition;
  • The walls aren’t directly exposed to extreme weather and heavy rain;
  • The home isn’t in a high-risk flooding zone;
  • The internal walls are not exposed to damp conditions;
  • There are no timber or steel frames used in the home’s construction.

Installing Cavity Wall Insulation

While some types of insulation can be installed by virtually anyone, cavity wall installation is best left to professional installers. This is because cavity insulation installation requires experience, training and specialised equipment to perform a high-quality install. The process goes like this.

  • Confirm Suitability – Any experienced installer will assess the home and look for existing insulation by inspecting it with a borescope. This will check the suitability factors that I mentioned above and will give you an idea of the general conditions of the walls. 
  • Hole Drilling – Once your home is confirmed as suitable for cavity wall insulation, the installation process will start. A series of holes between 2-3cm are drilled along the exterior wall at about one-metre intervals.
  • Injecting the Insulation – The insulation material is injected through the holes using specialist equipment, filling the cavity and providing an extra layer inside between the home and the external environment. The material used is generally beads or foam.

Finding an Installer

Cavity wall insulation is performed by an experienced installer, so you need to find a reputable one who will perform the work. Your installer should be a member of the British Board of Agreement, Cavity Insulation Guarantee Agency or The National Insulation Association. These organisations have placed safeguards to serve homeowners. Their websites should be the first place you start looking for a reputable professional. There, you can find registered installers. Furthermore, you should keep these tips in mind.

  • Get multiple quotes – It’s always a good idea to shop around. Ask multiple installers for quotes, and most of them will give you the full price, and offer no-obligation assessments of your house. 
  • Read the reviews – Reading through past customer experiences will give you a general idea of how good the insulation installer is. Read their reviews on sites like Check-a-Trade, Trustpilot and even their social media. 
  • Ask friends or colleagues – A colleague or friend recently installed insulation? Ask them about their experience with the installer.

You’ll experience the advantages of wall cavity insulation right after it’s complete. It will probably be guaranteed by the CIGA for up to 25 years, and you’ll get your certificate soon after it’s done. If you experience issues with your insulation, you should contact your installer immediately. They will work with you and find a solution, and in most cases, it’s something that can easily be fixed.

Read through our useful guide for more information

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