Approved Cavity Wall Insulation Installers

What is Cavity Wall Insulation?

Cavity wall insulation involves insulating the gap between the outer and inner walls of a building. Typically, the outer wall is constructed with bricks, while the inner wall may consist of concrete, structural clay, or brick. This method differs from solid stone walls, where there is no gap to fill and internal wall insulation is more suitable.

Cavity wall insulation is commonly fitted in residences equipped with cavity walls, characterised by two layers of brick or block separated by a gap. Its purpose is to reduce heat loss, improve energy efficiency, and decrease heating costs.

According to the Energy Savings Trust, approximately 33% of heat escapes through cavity walls. If your home’s walls are suitable, cavity wall insulation is one of the most efficient forms of insulation, along with loft insulation.

A professional assessment is crucial. Here are the key factors an installer should evaluate to determine the suitability of cavity wall insulation for your home:

Shown are the different types of wall suitable for either cavity wall or internal wall insulation. 

How does Cavity Wall Insulation Work?

Cavity wall insulation is a method used to fill the gap between a building’s inner and outer walls with insulating material, aiming to minimise heat loss and boost energy efficiency. Here’s a general overview of the process:

Cavity Wall Construction

Cavity walls typically comprise two layers of brick or block with a gap between them, providing room for insulation and moisture protection.

Selection of Insulation Material

Common options include mineral wool (like glass wool or rock wool) or polystyrene beads called cavity wall beads.

Drilling Holes

Small holes are drilled into the external wall at regular intervals to facilitate the injection of insulation material.

Injection of Insulation Material

The chosen material is injected into the gap through the drilled holes, expanding or filling the space.

Sealing of Holes

After filling the cavity, the drilled holes are sealed with mortar matched to the exterior wall’s appearance.

Inspection and Quality Control

A professional may inspect the installation to ensure uniform coverage and the absence of gaps or voids.

Key Benefits

Thermal Barrier: Insulation reduces heat transfer through walls, enhancing indoor comfort.

Energy Efficiency: Cavity wall insulation reduces the need for heating or cooling, potentially leading to energy savings.

Condensation Control: Helps mitigate dampness and mould by regulating interior moisture levels.

It’s crucial to evaluate a building’s suitability for cavity wall insulation and adhere to building regulations and standards when selecting materials and carrying out the installation.

Diagram showing how cavity wall insulation works

Benefits Of Cavity Wall Insulation

Cavity wall insulation offers homeowners several benefits, including improvements in energy efficiency, comfort, and potential cost savings.

Here are the key advantages:

Cavity wall insulation acts as a thermal barrier, reducing the transfer of heat through the walls. This helps to retain warmth in the winter, leading to a more energy-efficient home.

By reducing heat loss, cavity wall insulation can result in lower heating bills. A well-insulated home requires less energy to maintain a comfortable temperature.

Insulated walls help maintain more stable indoor temperatures. This means warmer interiors in the winter and cooler interiors in the summer.

Cavity wall insulation is often a quick and straightforward installation process that can be completed in a day. This minimises disruption to occupants.

A more energy efficient home results in lower carbon emissions. By reducing the need for heating, cavity wall insulation contributes to environmental sustainability.

Improving the energy performance of a property through insulation measures can enhance its market value. Many homebuyers appreciate energy efficient features.

In Scotland Government grants are available to encourage homeowners to install cavity wall insulation. These financial incentives will offset your installation costs.

Cavity wall insulation, when installed correctly, can be a long-lasting solution. It requires minimal maintenance and continues to provide benefits over the long term.

In addition to thermal benefits, cavity wall insulation can contribute to sound insulation. It helps reduce the transmission of external noise into the home, creating a quieter living environment.

Before proceeding with cavity wall insulation, it's recommended to consult with our affiliated insulation installers to evaluate your property's suitability and investigate potential grants.
Insulation Scotland


  • Professional Installation: As previously emphasised, professional installation is essential for cavity wall insulation to achieve its full effectiveness. Trained experts should handle the installation process to ensure consistent coverage and mitigate thermal bridging concerns.
  • Property Suitability: Cavity wall insulation may not be suitable for every building. It’s crucial to conduct a comprehensive assessment by professionals to determine the property’s suitability before proceeding.
  • Compliance with Regulations: Adherence to relevant building regulations and standards is critical during installation to ensure safety and optimal functionality of the insulation system.

Best Material For Cavity Wall Insulation

The selection of cavity wall insulation material hinges on diverse factors, encompassing building specifications, climate, and individual preferences. Here are some prevalent types of cavity wall insulation materials:

Mineral Wool (Glass Wool or Rock Wool)


Exhibits commendable thermal insulation properties.

Non-combustible and endowed with fire-resistant attributes.

Shows resilience against moisture absorption.

Offers potential for sound insulation.


Mandates professional installation to ensure uniform coverage.

Foam Insulation (Polyurethane or Polystyrene):


Boasts high thermal insulation capabilities.

Lightweight and facilitates easy installation.

Demonstrates resistance to moisture.

Renders a seamless and airtight seal.


Certain foams may emit gases during installation, necessitating proper ventilation.

Initial cost might be higher.

Cellulose Insulation


Crafted from recycled paper, rendering it environmentally friendly.

Effective thermal insulation performance.

Can be injected into the cavity.


May necessitate additives to enhance fire resistance.

Moisture resistance levels can vary.

Cavity Bead Insulation (Expanded Polystyrene Beads)


Lightweight and facilitates straightforward installation.

Possesses commendable thermal insulation properties.

Shows resistance to moisture.


Requires professional installation.

May experience settling over time, potentially affecting performance.

Cavity insulation beads are generally the best type of material to install.

Diagram shown external and internal walls with the cavity wall insulation beads installed in-between

Problems Due To Poor Installation

There has been some news articles in Scotland documenting problems with cavity wall insulation, almost always stemming from poor installation practices, which can lead to issues such as dampness and moisture. However, our partner installers have a track record of completing thousands of successful jobs over the years, ensuring proper installation.

Installing cavity wall insulation involves numerous steps, and it’s crucial to have experienced installers who are well versed in the process to avoid potential issues. One common problem is thermal bridging, where breaks in the insulation layer create direct pathways for heat to bypass the insulation material.

Potential consequences of thermal bridging include

Reduced Energy Efficiency: Thermal bridging can compromise the building’s overall energy efficiency, resulting in increased heat loss and higher energy bills.

Cold Spots and Condensation: Areas affected by thermal bridging may develop cold spots on internal walls, leading to condensation and dampness issues that affect occupant comfort and indoor air quality.

Mould Growth: Cold spots and condensation can create conditions conducive to mould growth, posing health risks and requiring remediation efforts.

Installing cavity wall insulation in listed buildings presents additional challenges due to their historic and protected status. Specific considerations and regulations must be followed to preserve the architectural and historic integrity of these properties. Listed buildings are officially recognised and protected for their special architectural or historic significance.

If you are put off cavity wall insulation, you can consider other options such as internal wall insulation and loft insulation

Damp and aged cavity wall insulation removal

Cavity Wall Insulation Removal and Replacement

If you’ve experienced issues with a previous cavity wall insulation installation, you have the option to address them through cavity wall insulation removal and replacement, also known as cavity wall extraction and refill.

Sometimes, cavity wall insulation may need to be replaced simply due to its age, especially if it was installed around 15 to 20 years ago with older, less effective materials. Here’s how the extraction and refill process typically works:

Cavity Wall Extraction Process

Assessment: A professional assesses the condition of the existing insulation and identifies any issues that need attention.

Extraction: Specialised equipment, like cavity wall extraction machines, is used to remove the old insulation material from the wall cavities. Small holes may be drilled in the walls to access the cavities without causing damage.

Thoroughness: Care is taken to ensure all old insulation material is completely removed to prepare for the refill.

Cavity Wall Refill Process

Insulation Material Selection: A suitable insulation material is chosen based on building requirements, climate, and energy efficiency goals. Options include mineral wool, foam insulation, or cellulose insulation.

New Installation: The selected insulation material is injected or blown into the wall cavities using specialised equipment, ensuring complete filling and a continuous barrier.

Quality Assurance: After refilling, a thorough inspection ensures proper installation and complete cavity filling.

Benefits of Removal and Replacement

Improved Energy Efficiency: New insulation enhances thermal performance, reducing heat loss and energy consumption.

Enhanced Comfort: Well insulated walls maintain consistent indoor temperatures and reduce drafts, improving comfort.

Moisture Management: Upgraded insulation can help address moisture issues and enhance indoor air quality.

Long-Term Savings: Efficient insulation leads to lower energy bills and potentially increases property value.

Cavity wall insulation removal and replacement can be cost effective, often qualifying for government grants. It’s one of the most efficient ways to upgrade a building’s thermal performance, promoting comfort, energy savings, and environmental sustainability.

Professional cavity wall insulation removal and replacement
Insulation Scotland

Cavity Wall Insulation Installers Edinburgh

Our insulation installer partners are highly experienced in cavity wall insulation, having completed thousands of successful installations. They follow a meticulous process to ensure your project is carried out efficiently and effectively.

If cavity wall insulation is not suitable for your home, we can discuss and provide alternative options that best fit your needs.

All the installers we collaborate with are fully approved, including certifications like TrustMark. This means they can install insulation under government grant schemes, ensuring compliance with quality standards and regulations.

Cavity Wall Insulation Grant Edinburgh

Cavity wall insulation is the most prevalent form of home insulation in Scotland in terms of demand, hence it is heavily supported by government grants to cover the installation cost. As well as cavity wall insulation grants, customers frequently seek grants for loft insulation,

Funding eligibility is determined by factors such as improving your home’s EPC rating. Several insulation grants are accessible, including the Home Energy Scotland grant and loan scheme, ECO 4 scheme, and the Great British Insulation scheme.

Insulation Scotland’s partners assist with the application process and subsequently install cavity wall insulation if you secure funding. For further information and to determine your eligibility for a grant¬†please call us or complete our short contact form.

Insulation Scotland

EdinburghCavity Wall Insulation Installers

Get A Cavity Wall Insulation Quote

Please complete the contact form provided below to schedule a no-obligation cavity wall insulation survey. Kindly allow up to 48 hours for one of our representatives to reach out to you via telephone to discuss further.

Instant Quote in Edinburgh

Please call us to discuss your requirements, if you have pictures of your walls, loft, roof or home layout please provide these to speed up the process.

Cavity Wall Insulation Across Scotland

Our team of insulation contractors and surveyors travel all over Scotland providing cavity wall insulation in Aberdeenshire, Angus, Argyll & Bute, Ayrshire, Clackmannanshire, Dumfries and Galloway, Dundee, East Ayrshire, East Dunbartonshire, East Lothian, Edinburgh, Glasgow, Falkirk, Fife, Highland, Inverclyde, Inverness, Midlothian, Moray, North Ayrshire, North Lanarkshire, Perth and Kinross, Renfrewshire, Stirling, South Ayrshire, South Lanarkshire, The Borders, West Dunbartonshire and West Lothian. 

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