Internal Wall Insulation
Internal wall insulation is an effective solution for improving the energy efficiency of your home. Therefore, by insulating the internal walls, residents can reduce heat loss, save on bills, and enhance the home environment. Below we delve into the importance of internal wall insulation, the types available, benefits, installation methods, and maintenance tips, providing you with everything you need to know about this essential home improvement.
What is Internal Wall Insulation?
Internal wall insulation involves adding insulating material to the inner surfaces of external walls. This method is particularly useful for older buildings with solid walls that lack cavity walls. Internal wall insulation creates a thermal barrier, preventing heat from escaping through the walls and keeping your home warmer during winter and cooler during summer.
IWI Installing Process
Under the ECO4 scheme, the installation of internal wall insulation must adhere to the highest standards to ensure optimal thermal efficiency and long-term durability. All installers participating in the ECO4 scheme must be Trustmark registered and comply with Ofgem’s delivery guidance. At Fairway Energy, we follow a meticulous process to install internal wall insulation in your home, ensuring quality, compliance, and maximum energy savings. Here’s how we do it:

Before Installation
Installing internal wall insulation requires professional installers to ensure optimal performance and compliance with building regulations. Before installing insulation, our team will assess the walls to determine the appropriate amount of insulation required. Similarly, check for any existing insulation that may need to be upgraded or removed and address any structural issues or dampness.
Next, we will clear the wall surfaces of any fixtures, fittings, and debris. Also, we will ensure that the walls are dry and clean. Furthermore, we will repair any cracks or damage to the walls and apply a damp-proof membrane if necessary to prevent moisture penetration.
Benefits of Internal Wall Insulation

Internal Wall Insulation Materials
The Internal Wall Insulation (IWI) System used by Fairway Energy consists of, glass mineral wool insulation batts, used for their thermal and acoustic benefits. It is a breathable insulation material, and is combined with extruded polystyrene (XPS) bonded to oriented strand board (OSB) for structure. This system is specified in the ECO4 scheme delivery guidance set by the regulator Ofgem.


Material Breakdown:
1. Glass Mineral Wool (Fiberglass)
- Made primarily from silica sand and recycled glass bottles.
- The fibres are spun from molten glass and formed into insulation batts.
2. Specialised Binder Technology
- A formaldehyde-free, bio-based binder used instead of traditional phenol-formaldehyde resins.
- Derived from rapidly renewable materials, reducing the environmental impact.
- Provides a soft feel, low odour, and improved indoor air quality.
3. Water-Repellent Treatment
- Helps maintain insulation performance and prevents mould growth.
- The fibres are treated to be moisture-resistant, reducing the risk of water absorption.
- A rigid, closed-cell insulation material that provides excellent thermal performance.
- High moisture resistance, making it ideal for reducing thermal bridging and preventing damp issues.
- A strong engineered wood panel that provides structural support.
- It helps with secure fixings for finishes like plasterboard.
- The XPS core acts as a thermal break, preventing heat loss through traditional timber or metal studs.
- The OSB strip allows for fixing and adds structural integrity.
- The Glass Mineral Wool Batts play a crucial role in thermal, acoustic, and fire performance. It is used in combination with XPS + OSB to enhance the overall insulation effectiveness.
Together, they create an energy-efficient and moisture-resistant insulation system.
Function In The IWI System


Certifications of the IWI System used By Fairway Energy
- British Board of Agrément (BBA) Certified, ensuring compliance with industry standards.
- BRE Green Guide A+ Rating for sustainability.
Other Types of Insulation Material
There are other types of internal wall insulation material, but these are not used for IWI on the ECO4 scheme:
Maintaining Internal Wall Insulation
Careful maintenance of internal wall insulation ensures longevity. Therefore, here are some tips for maintaining your internal wall insulation:
Internal Wall Insulation Installed on ECO4 Scheme









Conclusion
Internal wall insulation is a crucial aspect of a home’s energy efficiency. Likewise, it also offers numerous other benefits, including cost savings, and a more consistent temperature in your home. Therefore, by understanding the different types of insulation and the process to install them, you can make an informed decision to optimise your home’s EPC.
In summary, all insulation is a wise choice for any homeowner looking to reduce energy bills, enhance comfort, and contribute to environmental conservation. Therefore, embrace the advantages of internal wall insulation today and enjoy a more energy-efficient and comfortable home year-round.