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The UK's leading authority in Cavity Wall Insulation Extraction — delivering professional surveys, extraction and independent clearance certification.
Want to know more about our services? Call us today.
Freephone 03335 77 66 55Background
14 million homes in the UK have had Cavity Wall Insulation installed. The problem is that the UK's wet weather, high winds and icy conditions take their toll on the exterior of properties over time — leading to degraded brickwork and mortar which can allow water into the cavity. Once the insulation gets wet it is next to impossible to dry out, which over time allows damp to transfer to the inner property and can cause far more serious structural issues.
Oscar Onsite believes that currently there are over 3 million homes which have had Cavity Wall Insulation that has failed — many identified along the West coast of the UK suffering from damp, mould and related issues caused by blocked or impaired cavities.
Some Reasons Why Extraction May Be Necessary:
Because:
The Solution
Reinstate the cavities back to where they should have been before any insulation was introduced — inspecting wall ties and clearing the cavity of debris and materials that could contribute to damp course failure. Extraction companies must be certified by Oscar Onsite with all technicians individually Oscar Onsite accredited.
Oscar Onsite have written and launched the NVQ Level 2 in Cavity Wall Insulation Surveying and Extraction, available to all Oscar Onsite Members.
15M+
UK homes with Cavity Wall Insulation installed
6M+
Estimated may have incorrect or failing insulation
2 days
Average extraction time
100%
Independently verified clearance
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Our accredited surveyors will carry out a full technical inspection of your cavity wall insulation and provide a detailed report on its condition.
Book a SurveyFree Download
Download our comprehensive guide covering everything you need to know about cavity wall insulation — from installation risks to extraction and clearance certification.
Download Brochure (PDF)How It Works
The removal of cavity wall insulation should always be undertaken by a competent and experienced specialist contractor. Before any extraction works are recommended, a detailed inspection of the property should be completed to assess the condition of the existing insulation and determine whether it is contributing to dampness, moisture ingress, or other building performance issues.
As part of the assessment, a surveyor will typically carry out an inspection using specialist equipment, including borescope cameras, to examine the cavity and verify the condition of the insulation material. Following this investigation, recommendations can be made regarding the most appropriate remedial action.
Where cavity wall insulation extraction is required, the process generally involves the following stages:
Access Drilling
Small access holes are carefully drilled through the external mortar joints or brickwork to provide access to the cavity.
Airflow Introduction
Specialist extraction equipment introduces controlled airflow into the cavity, helping to loosen and mobilise the insulation material.
Vacuum Extraction
Industrial vacuum systems remove the insulation and associated debris from within the cavity wall.
Progress Inspection
Cavity inspections are undertaken using borescope cameras throughout the process to monitor progress and confirm effectiveness.
Final Verification
A final cavity inspection verifies the insulation has been successfully removed and identifies any defects or obstructions.
Reinstatement
Access holes are professionally reinstated, with mortar joints repaired and brickwork made good to match the existing finish wherever practicable.
Following completion of the extraction works, further recommendations may be provided where additional repairs or remedial measures are required to address any underlying building defects contributing to moisture ingress or damp-related issues.
Why Extract?
Having cavity wall insulation removed by an Oscar Onsite accredited contractor can bring significant improvements to your home's health, comfort and value. Below are the key benefits homeowners experience following a professional extraction:
Reduced energy bills
Once failed or damp insulation is removed, the thermal performance of your property can be restored and improved with appropriate remediation measures, reducing heat loss and lowering energy costs.
Warmer, drier home
Removing saturated or degraded insulation eliminates the moisture it retains, making your property warmer — especially during the colder winter months — and significantly reducing cold spots on internal walls.
Elimination of damp, mould and condensation
Failed cavity wall insulation is one of the leading causes of persistent internal damp and mould growth. Extraction addresses the root cause, protecting both your property and the health of its occupants.
Protection of structural integrity
Wet insulation can corrode wall ties, damage timber frames and suspended floors, and accelerate the degradation of mortar and brickwork. Removing it prevents further structural damage and expensive long-term repairs.
Increased property value
A property with a verified, independently certified clear cavity is far more attractive to buyers and mortgage lenders. An Oscar Onsite Clearance Certificate provides documented evidence that the cavity has been professionally assessed and cleared.
Peace of mind with accredited certification
All work carried out by Oscar Onsite accredited members is independently monitored and results in a formal Clearance Certificate — giving homeowners, surveyors and solicitors documented assurance of the work completed.
FAQs
Have questions? Speak with our expert team today, or visit our Support Hub for quick answers.
Next Steps
Having your property assessed by Oscar Onsite's experienced surveyors is the first step towards identifying and resolving issues associated with failed cavity wall insulation, penetrating damp, condensation, and mould growth. Defective or saturated cavity wall insulation, combined with external building defects, can significantly affect the performance of a property and lead to ongoing moisture-related problems if left unaddressed.
At Oscar Onsite, our qualified specialists provide comprehensive cavity wall inspections and independent technical assessments to accurately identify the root cause of damp-related concerns. Where failed cavity wall insulation is found to be contributing to moisture ingress, we can recommend and undertake appropriate remedial measures, including cavity wall insulation extraction and associated corrective works.
Accurate diagnosis is essential. Misidentifying the source of dampness can result in unnecessary expenditure and ineffective remedial works. Our surveyors adopt a practical, evidence-based approach to investigating building defects, ensuring property owners receive clear, impartial advice and cost-effective solutions tailored to their specific circumstances.
Our cavity wall surveyors can inspect your property, assess the condition and suitability of the existing cavity wall insulation, identify any associated defects, and provide professional recommendations on the most appropriate course of action.
Get In Touch
Complete the form and one of our team will be in touch to arrange your Cavity Wall Insulation Extraction — carried out by Oscar Onsite accredited technicians and independently certified upon completion.
Call Us Freephone
03335 77 66 55Email Us
office@oscar-onsite.co.ukOpening Hours
Mon–Fri, 9:00am – 5:00pm
All extraction work is carried out by NVQ-qualified technicians and independently certified with an Oscar Onsite Clearance Certificate upon completion.