Cavity Wall Insulation: The Ultimate Guide to a Warmer, More Energy-Efficient Home
It all begins with an idea.
Are you tired of rising energy bills and a home that struggles to stay warm in winter? Cavity wall insulation could be the solution you’ve been looking for! In this blog post, we’ll break down everything you need to know about cavity wall insulation, its benefits, and why now is the perfect time to invest in it.
What Is Cavity Wall Insulation?
Many homes built after the 1920s feature cavity walls — walls made of two layers (an inner and outer wall) with a gap or "cavity" in between. Originally, this gap was designed to reduce moisture from entering the home. However, it also allows heat to escape, leading to higher energy bills and a colder living space.
Cavity wall insulation involves filling this gap with insulating materials (like mineral wool or polystyrene beads) to reduce heat loss and improve your home's energy efficiency.
The Benefits of Cavity Wall Insulation:
✅ Lower Energy Bills:
By preventing heat from escaping, cavity wall insulation can reduce your energy bills by up to £250 per year!
✅ Warmer Home All Year Round:
Enjoy a more comfortable living space with less heat loss in the winter and better temperature regulation in the summer.
✅ Reduce Your Carbon Footprint:
Using less energy means your home produces fewer carbon emissions — great for both your wallet and the planet!
✅ Boost Property Value:
An energy-efficient home with improved insulation is more attractive to buyers and can increase your property’s value.
✅ Quick and Hassle-Free Installation:
Cavity wall insulation can usually be installed in a few hours with minimal disruption to your home.
Types of Cavity Wall Insulation: Which One Is Right for Your Home?
When it comes to cavity wall insulation, there are several materials to choose from, each with its own benefits. The right option for your home depends on factors like your property's age, wall structure, and specific energy efficiency goals. Below is a breakdown of the most popular types of cavity wall insulation to help you make an informed decision.
1️⃣ Mineral Wool (Glass or Rock Wool)
What is it?
Mineral wool is one of the most commonly used cavity wall insulation materials. It consists of fine fibers made from molten glass or rock, spun into a dense, wool-like material.
Benefits:
✅ Excellent thermal insulation properties.
✅ Provides good soundproofing, reducing external noise.
✅ Water-repellent and fire-resistant.
✅ Affordable and widely available.
Best For:
Homes in areas with high external noise.
Properties that need moisture-resistant insulation.
2️⃣ Polystyrene Beads (EPS Beads)
What is it?
Polystyrene beads, also known as expanded polystyrene (EPS) beads, are small, lightweight spheres injected into the wall cavity. The beads are often bonded together using an adhesive during installation to prevent settlement.
Benefits:
✅ High thermal efficiency with minimal moisture absorption.
✅ Easy to install, even in hard-to-reach areas.
✅ Less invasive, requiring fewer drilling holes during installation.
✅ Can be used in narrow wall cavities.
Best For:
Properties with narrow or uneven cavities.
Homes in damp or moisture-prone areas.
3️⃣ Polyurethane (PUR) Foam / Urea-Formaldehyde Foam
What is it?
Polyurethane or urea-formaldehyde foam is a liquid-based insulation material that is injected into the cavity, where it expands and hardens to fill gaps and cracks.
Benefits:
✅ Excellent at sealing gaps and cracks, creating an airtight barrier.
✅ High thermal insulation value (ideal for maximizing energy efficiency).
✅ Can be applied in irregular or narrow cavities.
Best For:
Older properties with uneven or narrow cavities.
Homes where maximum insulation efficiency is needed.
Note: Urea-formaldehyde foam was more commonly used in the past but has fallen out of favor due to concerns about off-gassing and long-term durability. Modern polyurethane foams are safer and more reliable.
4️⃣ Phenolic Foam Beads
What is it?
Phenolic foam beads are a newer type of cavity wall insulation made from high-performance phenolic resin. These beads are lightweight and offer superior insulation properties.
Benefits:
✅ One of the best thermal insulators available.
✅ Highly fire-resistant and moisture-resistant.
✅ Long-lasting and durable.
Best For:
Homes seeking the highest energy efficiency.
Properties in areas prone to dampness or high humidity.
Which Cavity Wall Insulation is Right for You?
On a Budget? Mineral wool offers great value for money.
Damp-Prone Area? Polystyrene beads or phenolic foam beads are ideal.
Max Energy Savings? Opt for polyurethane or phenolic foam.
Older Homes with Irregular Cavities? Foam-based insulation works bes
How Is Cavity Wall Insulation Installed?
Assessment: A professional surveyor will inspect your property to ensure it's suitable for cavity wall insulation.
Drilling: Small holes (about the size of a 10p coin) are drilled into the external walls.
Filling: Insulation material is injected into the cavity through the holes.
Sealing: The holes are filled and matched to the existing brickwork, leaving no visible traces.
The whole process is quick, non-invasive, and typically completed within a day.
Is Your Home Suitable for Cavity Wall Insulation?
Your home is likely suitable if:
It was built between the 1920s and 1990s.
The external walls are cavity walls (not solid brick).
The cavity is at least 50mm wide and free of debris.
The walls are in good condition without major damp issues.
Not sure? A free home energy assessment can determine if your property qualifies!
Is Funding Available for Cavity Wall Insulation?
Good news! Government-backed grants and energy company schemes are often available to help homeowners cover the cost of cavity wall insulation. In some cases, the installation could be fully funded or offered at a reduced price. With new Schemes such as The Great British Insulation Scheme funding is not reliant on homeowner circumstances.
Contact us today to see if you qualify for funding and start saving on your energy bills! https://wa.me/447123456789
Final Thoughts:
Cavity wall insulation is one of the most cost-effective ways to improve your home’s energy efficiency, lower your bills, and reduce your carbon footprint. With available grants and the promise of a warmer, greener home, there’s no better time to invest in cavity wall insulation.