Free Cavity Wall Insulation FAQs
Here are some FAQ’s. If you have any other questions please give us a call on 0800 8 10 10 60
You can have a look at this 6 minute video to see the process.
We insulate cavity walls by blowing polystyrene beads into the cavity, typically from the outside, though it can be done from inside the house under certain conditions.
Small 22mm holes, which are slightly smaller than a 2p coin, are drilled into the external walls in a specific pattern. This pattern is outlined in the British Board of Agrément (BBA) certificate for the insulation material being used.
Using specialized equipment, the insulation along with an adhesive is blown into the holes. The adhesive sets in about 20 minutes, forming the polystyrene beads into a loose, cohesive block.
The holes are then filled with cement, and carefully color-matched to blend with the existing mortar or render.
Filling cavity walls is not a DIY task. For a typical 3-bed semi-detached house, the entire process takes around 3 hours.
Most of our customers are impressed by how quickly and neatly the work is completed.
Additionally, the work comes with a 25-year guarantee from CIGA, the government-backed Cavity Insulation Guarantee Authority, providing complete peace of mind.
To find out if you qualify, or to book a free no obligation survey, complete our enquiry form or give us a call
or call us on 0800 8 10 10 60 or 07960 799681 and speak to one of our cavity wall experts.
We exclusively install “SuperBead” polystyrene beads, not “RockWool” (fibre), as they are a superior material for cavity wall insulation, although slightly more expensive.
“SuperBead,” used for free cavity wall insulation near me, has been certified by the British Board of Agrément for the following benefits:
- Thermal Efficiency: “SuperBead” insulation offers excellent thermal conductivity, rated at 0.035.
- Water Resistance: It effectively resists the transfer of water across the cavity, ensuring added protection.
- Condensation Control: “SuperBead” helps reduce the risk of condensation within the home.
- Fire Safety: It does not compromise the fire resistance properties of the wall.
- Durability: “SuperBead” is rot-proof, water-resistant, and stable enough to provide effective insulation for the building’s lifetime.
“SuperBead” is up to 20% more efficient than fibre insulation like RockWool, reducing heat loss through walls by approximately 70%. An uninsulated home typically loses around 35% of its heat through the walls, meaning wall insulation can save about 25% on your heating bills.
In addition, installing “SuperBead” requires around 30% fewer holes in the wall, and the holes themselves are smaller than those needed for fibre insulation.
These beads are rigorously tested to ensure they don’t deteriorate over time. They are fully fire-resistant and approved for use even in extreme conditions.
Yes, it comes with a 25-year guarantee provided by the Cavity Insulation Guarantee Agency (CIGA).
CIGA offers independent 25-year guarantees for free cavity wall insulation near me, installed by registered professionals across the UK and Channel Islands. However, this guarantee is only issued if the property passes a CAS (Cavity Assessment Survey).
A grant for insulation will not be approved without a CIGA guarantee.
The Government views cavity wall insulation as “the most cost-effective energy-saving measure for most homes,” and it plays a key role in reducing carbon emissions.
CIGA was created in partnership with the Government’s Energy, Environment, and Waste Directorate (part of DETR) to provide homeowners with a consistent, independent guarantee that covers defects in both materials and workmanship.
According to independent research by the Department of the Environment, Transport, and the Regions (DETR), cavity wall insulation is a highly reliable process. Issues are extremely rare, but in the event of a problem, CIGA has the expertise to resolve it quickly. The new CAS survey further reduces the risk by ensuring only suitable walls are insulated.
CIGA also manages the Cavity Wall Insulation Self Certification Scheme (CWISC) alongside the British Board of Agrément. This scheme assures homeowners that work carried out by registered contractors complies with building regulations.
The straightforward answer is, “I can’t tell you without conducting a survey.” However…
If your home was built after 1925, it likely has external walls made of two layers of brick with a gap (cavity) between them, held together by wall ties. This is known as a cavity wall.
Free cavity wall insulation near me fills this gap, helping to retain warmth and save energy. It can also help reduce or eliminate condensation inside the house, especially if your external walls are prone to this issue.
Your home is typically suitable for free cavity wall insulation in Cardiff if:
- The external walls have unfilled cavity walls
- The cavity is at least 50mm wide
- The masonry or brickwork is in reasonably good condition
But it’s not quite that simple.
As part of the initial process, we also carry out a Cavity Assessment Survey, which is administered and audited by the Installation Assurance Authority (IAA).
The survey assesses the suitability of the walls for insulation through an in-depth examination of the property.
This includes drilling small test holes in each elevation of the wall, inserting a borescope to inspect the cavity, and taking photographs and measurements of its depth.
All walls are carefully inspected for issues like cracks, unfilled holes, and any necessary remedial work, which must be addressed before insulation can proceed.
Gutters and downpipes are also checked for leaks, blockages, and proper drainage.
The survey, which is free of charge, typically takes about two hours to complete.
Afterward, the report and photos are uploaded to the IAA platform for auditing.
This process is part of the enhanced quality control measures included in the new free Cavity Wall Insulation Grant scheme.
If you notice damp patches on the inside of your external walls, they must be addressed before any insulation can be installed.
In fact, if the property suffers from damp, it will not pass the CAS (Cavity Assessment Survey), and we won’t be able to install cavity wall insulation.
To qualify for a grant, a 25-year guarantee must be issued, which only happens if the property passes the CAS survey. So, if your home has damp issues, it will fail the survey, meaning no grant can be offered—plain and simple.
However, if you’re seeing “black mould or spots,” it’s likely due to condensation rather than structural damp.
In about 90% of cases, condensation is related to lifestyle habits, not a problem with the building itself. Still, cavity wall insulation can help reduce or eliminate the black mould by keeping the internal walls warmer.
No, not all houses with cavity walls are suitable for insulation.
If we look back before 1920, most homes didn’t have cavity walls. Instead, they were constructed with stone or solid brick (two brick walls side by side). A few exceptions exist, such as the mill houses in Lancashire and Yorkshire, which were built with two stone walls and a cavity between them. These should not be insulated due to various potential issues.
Solid walls, whether stone or brick, often suffered from dampness, which led to illnesses like pneumonia. As a result, many people were at risk.
Cavity walls were introduced as a solution. These featured two brick walls with a gap between them (a cavity), and by the 1920s, more homes began to adopt this design. By 1930, cavity walls had become the standard.
Homes built after 1930 are generally suitable for cavity wall insulation, but I must emphasize – this is always subject to a survey.
There are three major exceptions:
- Concrete properties, typically former council houses, which may have unfilled cavities. Insulating them can lead to “Concrete Cancer,” so it’s not recommended.
- Timber-framed properties, where a wooden frame is attached to the inside of a brick external wall and covered with plasterboard. The wooden frame contains insulation, making cavity wall insulation unnecessary.
- Properties built after 1982 should have been insulated during construction to meet the building regulations introduced that year. However, many homes built in the 1980s and 2000 were left uninsulated. These may still be suitable for insulation, subject to a survey.
Yes, installing free cavity wall insulation can help lower your fuel bills, reduce your carbon footprint, and may also assist in reducing or eliminating condensation.
Here’s a breakdown of where heat is typically lost in a home:
- Walls: 35%
- Roof: 25%
- Floor: 15%
- Draughts: 15%
- Windows: 10%
By insulating the cavity walls, you can significantly reduce the 35% heat loss from walls, helping your home retain warmth more efficiently.
Cavity wall insulation offers a range of benefits, including:
- Energy Efficiency: It helps reduce heat loss, making it easier to maintain a comfortable indoor temperature, which translates to lower energy bills since less heating is required.
- Cost Savings: By cutting down on the energy needed to heat your home, insulation results in long-term savings on heating costs.
- Increased Comfort: Insulating the walls creates a more even and comfortable indoor climate by reducing drafts and cold spots, making your home more pleasant year-round.
- Environmental Impact: Better energy efficiency leads to lower carbon emissions from heating systems, reducing your home’s environmental footprint and carbon impact.
- Condensation Control: Insulation can help prevent condensation on the inside walls, which can cause dampness and mold. Keeping the interior walls warmer helps reduce the risk of condensation.
- Property Value: Energy-efficient improvements like cavity wall insulation can boost your home’s value, as buyers increasingly prioritize energy-efficient features.
- Noise Reduction: It also provides some soundproofing, helping to reduce outside noise, especially beneficial in busy or noisy areas.
- Quick Installation: Installation is fast and minimally disruptive—an average semi-detached house can be insulated in about three hours.
According to the Cavity Insulation Guarantee Agency (CIGA), damp issues occur in approximately 3 out of every 1,000 homes that have cavity wall insulation (CWI) installed.
The majority of these damp problems are historical, resulting from unsuitable insulation being installed in inappropriate walls. Rockwool was once the standard material for CWI but has since been replaced by polystyrene beads, which offer superior performance.
However, early versions of polystyrene beads—small, white, soft beads like those found in bean bags—also posed problems. These early beads were not effective at repelling water and could contribute to damp issues.
Today, cavity wall insulation uses larger grey or silver polystyrene beads, often in a variety of sizes. These modern beads are designed to repel water, significantly reducing the risk of moisture problems.
The primary issue arose from improper installation practices. Salespeople would sometimes promise free CWI without conducting proper pre-installation surveys. As a result, homes that should not have been insulated were insulated, leading to complications.
Improvements in Quality Control
In April 2017, the British Board of Agrément (BBA) was tasked with ensuring that inappropriate homes would no longer be insulated, leading to the creation of the Cavity Assessment Surveillance Scheme (CASS).
The BBA certifies that building materials are fit for purpose and defines how they should be used. In October 2018, CIGA took over the scheme, which is now monitored by the Insulation Assurance Authority (IAA).
The CASS process involves a comprehensive survey of the property to determine its suitability for insulation. This survey, which takes around two hours, includes factors such as the condition of the walls, the depth of the cavity, the damp-proof course, and the state of gutters and downpipes. Leaky gutters and downpipes are common causes of dampness in homes.
Survey data, including photographs of the cavity, is uploaded to the IAA platform for auditing. Every survey undergoes a desktop audit, and 1 in 10 properties receive an on-site audit by an IAA surveyor to ensure accuracy.
This level of quality control is expected to significantly reduce the issue of insulating inappropriate homes and, consequently, the risk of dampness caused by cavity wall insulation.
Up until 2017, CIGA reported issues in 3 out of every 1,000 homes with CWI, but the introduction of the CAS survey is expected to lower this number significantly.
Yes, free cavity wall insulation can effectively reduce condensation.
Condensation occurs when warm, moist air encounters a cold surface. The warmer the air, the more moisture it can hold. However, when this warm air comes into contact with a colder surface, the air cools, releasing some of its moisture onto the surface. If this moisture is not quickly dried, it can lead to the growth of black mould.
By insulating the cavity walls, the internal walls of the house remain warmer, which significantly reduces the likelihood of condensation forming. As a result, free cavity wall insulation can help to minimize or even eliminate condensation and prevent the development of black mould.
The government has set strict legal targets to cut carbon emissions, but rather than tackling it directly, they placed the responsibility on gas and electricity companies. This initiative is known as the Energy Company Obligation (ECO).
We all contribute to this through a “green levy” added to our fuel bills. Approximately 6% of our gas bills and 11% of our electricity bills go towards funding this effort.
So, while the goal is to reduce carbon emissions, it’s worth noting that, as always, the cost ultimately falls on consumers.
There are three pathways to qualify for a grant:
- The General Group
- The “Low Income” Group
- LA Flex Funding
The General Group Criteria:
To qualify through this group, you need to meet two key requirements:
- Council Tax Band: In Wales, your property must fall under bands A, B, C, D, or E. In England, it must be in bands A to D. You can verify your council tax band on the Gov.UK website. ✔
- Energy Performance Certificate (EPC) Rating: Your property’s EPC rating must be D, E, F, or G, which you can find on the EPC Register. ✔
These conditions apply to both homeowners and private renters (with the landlord’s consent). However, private tenants must also receive a qualifying benefit for free cavity wall insulation.
The “Low Income” Group Criteria:
To qualify under this group, you must be receiving one of the following benefits, and your EPC rating must still be D, E, F, or G:
- Pension Credit
- Income-Based Job Seekers Allowance
- Universal Credit (no income threshold)
- Income-Related Employment and Support Allowance
- Tax Credits (including Working and Child Tax Credits) – no income threshold
- Income Support
- Housing Benefit – NEW
- Child Benefit/Family Allowance (subject to income thresholds, as outlined in the table below)
Child Benefit Qualification Matrix: Your household income must not exceed the threshold based on your household composition and number of children:
| Number of Children | 1 Adult Household | 2 Adult Household |
|---|---|---|
| 1 | £19,900 | £27,500 |
| 2 | £24,800 | £32,300 |
| 3 | £29,600 | £37,200 |
| 4 | £34,500 | £42,000 |
LA Flex Funding Route:
This qualification route considers factors other than benefits. There are two ways to qualify under LA Flex:
- Route 1: Total gross household income must be no more than £31,000 annually.
- Route 2: Someone living at the property must suffer from one of the following conditions:
- Cardiovascular condition
- Respiratory disease
- Limited mobility
- Immunosuppression
This flexible approach allows more households to qualify for the grant based on individual circumstances.
We handle everything for you, so there’s no need to stress over paperwork.
During the survey, we take care of the entire grant application process and confirm your eligibility.
Once the work is complete, we request the grant funds, which are paid directly to us.
All you need to do is relax and enjoy reduced energy bills and a smaller carbon footprint.
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