Cavity Wall Insulation Installers in Cheshire & the North West
Reduce heat loss through your walls by up to 35%, saving up to £410 per year on energy bills.
We’re Insul8, Trustmark-registered cavity wall insulation installers based in Nantwich, Cheshire. We survey, assess and install cavity wall insulation for homeowners across the North West, Shropshire, Staffordshire and the West Midlands.
Not every property is suitable for cavity wall insulation, and if you already have insulation that isn’t performing, the solution may be removal and replacement rather than a new install. That’s why we start every project with a thorough assessment, so you only pay for work that will actually make a difference.
Request a FREE Cavity Wall Assessment
Is Your Home Suitable for Cavity Wall Insulation?
Not every property is right for cavity wall insulation, and installing it in the wrong home can cause more problems than it solves. That’s why we survey every property before we quote.
Across Cheshire, Greater Manchester and the North West, the majority of the housing stock from the 1930s onwards was built with cavity walls. Semi-detached and terraced properties in towns like Nantwich, Crewe, Stockport and Warrington are typically good candidates, as are post-war estates across the region. Older properties in areas like Chester, Shrewsbury and parts of Manchester may have solid walls or narrower cavities that need assessing first.
Your property may not be suitable for cavity wall insulation if:
- The brickwork or pointing is damaged or in poor condition
- There is existing unresolved damp or penetrating moisture
- The property is in a highly exposed location with severe wind-driven rain
- The cavity is narrower than 50mm
- There is rubble or debris in the cavity
If you’re unsure whether your home has cavity walls or whether it’s suitable, that’s exactly what our free assessment is for. We’ll inspect your property, check the cavity, and give you an honest recommendation. If insulation isn’t right for your home, we’ll tell you.
Our Survey and Assessment Process
Every project begins with a free, no-obligation cavity wall assessment at your property. We carry out surveys across Cheshire, Greater Manchester, Shropshire, Staffordshire and the surrounding areas. This isn’t a quick glance at your brickwork. It’s a thorough inspection to make sure insulation is the right solution for your home.
During the assessment, we check:
External walls: We inspect the condition of your brickwork, mortar joints, pointing and render. Any damage needs to be repaired before insulation is installed, otherwise moisture can become trapped in the cavity.
Cavity inspection: Using a borescope (a small camera inserted through a drilled test hole), we examine the inside of your cavity. We’re checking for rubble, debris, existing insulation, or signs of moisture. This tells us whether the cavity is clean, clear and suitable.
Cavity width: We measure the cavity gap to confirm it meets the minimum 50mm width required for effective insulation.
Damp and moisture: We check for signs of penetrating damp, rising damp, or condensation issues. If damp is present, it needs resolving before insulation goes in. Insulating over a damp problem makes things worse, not better.
Ventilation: We check that air vents, airbricks and any combustion appliance flues are clear and functioning correctly. These must remain unobstructed after installation.
Once the assessment is complete, we’ll give you an honest recommendation. If your home isn’t suitable, we’ll tell you and explain why.
Book your free cavity wall assessment → or call 01270 814145
How We Install Cavity Wall Insulation
Our installers are fully trained, Trustmark-registered professionals based in Cheshire and covering the North West and Midlands. Here’s what happens on installation day:
1. Pre-installation checks
Before any drilling begins, we carry out final checks on ventilation, combustion appliances (boilers, gas fires) and confirm the drill pattern for your property.
2. Drilling
We drill small holes, approximately 22mm in diameter (roughly the size of a 20p coin), into the mortar joints of your external walls. Holes are spaced evenly in a diamond pattern to ensure complete, consistent coverage of the cavity.
3. Injection
Using specialist equipment, we inject the insulation material into the cavity at controlled pressure. The material flows through the cavity, filling it evenly from bottom to top. We monitor the fill to ensure there are no gaps or voids.
4. Sealing
Once the cavity is fully filled, every drill hole is sealed with colour-matched mortar, blended as closely as possible to your existing pointing.
5. Post-installation checks
After installation, we re-test combustion appliances and confirm that all ventilation points (airbricks, underfloor vents and flues) are clear and unobstructed.
Typical installation takes 2 to 4 hours depending on the size and layout of your property. All work takes place on the outside of your home, so there’s minimal disruption inside.
Ready to get started? Book your free assessment → or call 01270 814145
The Insulation We Use: Thermabead Carbon Saver
Every installer should be able to tell you exactly what they’re putting in your walls. We install Thermabead Carbon Saver, a grey, graphite-enhanced EPS (expanded polystyrene) bead, injected with a water-based bonding agent that locks the beads together inside the cavity. It’s certified under BBA Agrément 15/5181 and KIWA/BDA Agrément BAW-18-061-S-A-UK, independent approvals you can look up and verify.
The bonded-bead system flows into every part of the cavity, filling around wall ties and awkward corners without leaving cold spots. Because the beads are bonded, the fill doesn’t slump or settle over time, so gaps don’t open up at the top of the wall years later. It’s water-resistant and rot-proof, it won’t carry moisture across the cavity to your inner wall, and its declared thermal conductivity is 0.032 W/m·K. Carbon Saver is also BBA-approved for cavities as narrow as 40mm in standard exposure, narrower than many bead systems will treat, though a 50mm minimum still applies in areas exposed to severe wind-driven rain. Our survey confirms which applies to your property.
We've pulled a lot of failed insulation out of cavities over the years, and it shapes what you choose to put in. We use Thermabead Carbon Saver because the bead-and-bonding-agent system fills a cavity completely, around wall ties, into awkward returns, and it doesn't slump or settle the way some older fills do. It's water-resistant, so it doesn't hold moisture against the inner leaf. And because it's BBA-approved down to a 40mm cavity in standard exposure, we can treat a lot of properties that wouldn't suit a standard bead, though in exposed spots we'll still hold to a 50mm minimum. The survey tells us which applies. If a property genuinely isn't suitable, we say so. But the right product in the right cavity is a 25-year decision, and this is the one we trust.
Matthew Hodgson, Technical Director, Insul8
Already have insulation but still feel cold or damp?
If your walls still feel cold, rooms heat unevenly, or you’ve noticed damp or mould since having insulation installed, that’s a sign something isn’t right.
In these cases, a standard installation might not be the answer.
We offer a full cavity wall insulation removal and replacement service, where we extract faulty insulation and refill your cavity properly.
How much does cavity wall insulation cost?
As a relatively low-cost way to enhance your home’s energy efficiency, it comes with an initial financial cost that varies by property type.
- Mid terrace: starting from £1,500
- Semi-detached: starting from £2,700
-
Detached: starting from £4,300
*Costs taken from the Energy Saving Trust and are used as a guide only.
For a more detailed breakdown of typical cavity wall insulation costs and what affects them, see our Cavity Wall Insulation Cost Guide.
How to Choose a Cavity Wall Insulation Installer
If you’re searching for cavity wall insulation installers near you, the quality of the installer matters as much as the insulation itself. Choosing the right local contractor is the single most important factor in whether your insulation performs well or causes problems down the line. Here’s what to look for:
Trustmark registration. Trustmark is the government-endorsed quality scheme. A Trustmark-registered installer has been independently assessed for technical competence, customer service, and trading practices. It also gives you access to consumer protection if anything goes wrong.
A proper pre-installation survey. Any reputable cavity wall insulation company will survey your property before quoting. This should include a borescope cavity inspection, checks on brickwork condition, cavity width measurement, and a damp/moisture assessment. If an installer quotes without surveying, walk away.
Named materials with BBA or KIWA certification. An approved installer should be able to tell you exactly which insulation product they’ll use, its certification number, and why it’s suitable for your property. Vague answers about “standard insulation” are a red flag.
A 25-year insurance-backed guarantee. This is standard from any reputable installer. The guarantee should be backed by an independent body such as the IAA (Installation Assurance Authority) or CIGA (Cavity Insulation Guarantee Agency), not just the installer’s own warranty.
Genuine customer reviews. Check independent platforms like Trust a Trader, Checkatrade, or Google Reviews. Look for reviews that mention specific details about the work, not just generic praise.
Clear, written quotes. A professional cavity wall insulation firm will provide a detailed written quote after the survey, covering the materials, the scope of work, the cost, and the guarantee. No hidden extras, no verbal-only pricing.
Insul8 meets all of these criteria. We’re Trustmark-registered, based in Nantwich, Cheshire, and we survey every property in person before quoting. We use BBA-certified materials, and every installation comes with a 25-year insurance-backed guarantee. We cover Cheshire, Greater Manchester, Shropshire, Staffordshire and the surrounding areas.
Book your free survey → or call 01270 814145
Real homes. Real results.
Frequently asked questions
No. Some properties aren’t suitable due to solid wall construction, narrow cavities (under 50mm), damaged brickwork, high exposure to wind-driven rain, or existing unresolved damp. We always carry out a thorough assessment before recommending any work.
We inspect your external brickwork and pointing, check the cavity width and condition using a borescope camera, assess for damp or moisture issues, and review ventilation. You’ll get an honest recommendation and a written quote, with no obligation.
Most properties are completed in 2 to 4 hours. All work is carried out externally, so disruption to your home is minimal.
Starting prices are approximately £1,500 for a mid-terrace, £2,700 for a semi-detached, and £4,300 for a detached property. Your actual cost depends on property size, cavity width, and materials. We provide a clear written quote after the assessment.
We install Thermabead Carbon Saver – a grey, graphite-enhanced EPS bonded-bead system, certified under BBA Agrément 15/5181 and KIWA/BDA Agrément BAW-18-061-S-A-UK. It gives a complete cavity fill with no settling over time, it’s water-resistant and rot-proof, and it’s approved for cavities as narrow as 40mm in standard exposure. We confirm it’s the right choice for your property during the free survey.↑
Yes. After the assessment, you’ll receive a detailed written quote covering materials, scope of work, cost, and guarantee. No hidden extras.
When installed correctly in a suitable property, no. Problems arise when insulation is installed in properties that aren’t suitable or when the work is done badly. Our assessment process is designed to identify and avoid these risks. For more detail, read our guide: Can Cavity Wall Insulation Cause Damp and Mould?
We offer a full cavity wall insulation removal and replacement service. We extract the old insulation, inspect and clean the cavity, then re-insulate properly.
Yes. Every installation comes with a 25-year insurance-backed guarantee covering defects in workmanship and materials.
We typically book assessments within a few days across our service area. Call 01270 814145 or request an assessment online and we’ll confirm a time that works for you.
We’re based in Nantwich, Cheshire, and cover a wide area including Cheshire (Crewe, Sandbach, Congleton, Northwich, Knutsford, Macclesfield, Chester), Greater Manchester (Manchester, Stockport, Altrincham, Warrington), Shropshire (Shrewsbury, Telford), and Staffordshire (Stoke-on-Trent, Stafford). Contact us to check if we cover your area.
Look for a Trustmark-registered installer who carries out a full property survey before quoting, uses BBA-certified materials, and provides a 25-year insurance-backed guarantee. Insul8 meets all of these criteria and covers Cheshire, Greater Manchester and the surrounding areas. Book a free assessment or call 01270 814145.
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