Best Loft & Wall Insulation — 25mm (2026)
1 loft & wall insulation matching size “25mm”, hand-picked from UK Amazon listings.
Not sure which one to pick? Read our Best Loft & Wall Insulation UK (2026) guide.
This range of 25mm Loft & Wall Insulation is designed to provide effective thermal protection for your loft space or interior walls. Manufactured from mineral wool, a highly fibrous material renowned for its excellent insulation properties, these boards offer a significant reduction in heat loss, helping you maintain a comfortable temperature and lower energy bills. The 25mm thickness provides a good balance between thermal performance and ease of installation, making it suitable for a variety of applications within your home.
These mineral wool boards are non-combustible, meeting stringent fire safety standards crucial for loft environments. They’re also breathable, allowing moisture vapour to escape which is essential in preventing condensation build-up – a common cause of damp and mould growth. Installation is straightforward with minimal tools, making it a suitable project for both experienced DIY enthusiasts and those new to home improvements.
Specifically formulated for use as loft and wall insulation, this 25mm variant offers a robust solution where space is at a premium. It's designed to fit snugly into standard loft cavities and can be cut to size using a utility knife, minimising waste. Remember to always consult building regulations before undertaking any insulation project to ensure compliance with current standards.
#1 Pick
25mm Multi-Purpose Jabite Insulation Boards – Pack of 9 | Thermal Foam Panels for Floor, Wall, Roof & Underfloor Heating | Lightweight, Moisture Resistant, Easy to Cut & Install- Foam Insulation Board
- 25mm
£28.99
Pros
- Lightweight rigid foam panels are easy to cut and handle without mineral wool itch
- Pack of 9 boards suits floor, wall, roof or underfloor heating insulation jobs
- Moisture-resistant foam holds up better than fibre insulation in damp areas
Cons
- Foam boards offer less sound deadening than mineral wool alternatives
FAQ
What type of material is this 25mm Loft & Wall Insulation made from?+
These boards are constructed from mineral wool, a natural fibre product known for its excellent thermal resistance and fire protection qualities. Mineral wool’s inherent properties make it an ideal choice for insulation applications.
How thick is the insulation?+
The insulation has a thickness of 25mm. This specific dimension is chosen to provide effective thermal performance while remaining manageable for installation in lofts and walls.
Can I cut these boards to fit my space?+
Yes, you can easily cut these mineral wool boards using a utility knife or saw. It’s recommended to use a sharp blade and exercise caution when cutting to ensure clean edges.
Is this insulation suitable for damp environments?+
Mineral wool is breathable, allowing moisture vapour to escape. This is crucial in preventing condensation build-up and reducing the risk of dampness, but thorough preparation and ventilation are still recommended.
What’s the fire rating of these boards?+
These boards meet stringent UK fire safety standards, classified as Class 0, indicating they produce no smoke or flame when exposed to heat. This offers a significant level of protection in case of a fire.
How much does this insulation reduce heat loss?+
The thermal conductivity of mineral wool is relatively low, meaning it resists the flow of heat effectively. Typically, you can expect a reduction in heat loss of around 0.17 W/m²K with these boards - check manufacturer specifications for precise figures.
Do I need any special tools to install this?+
You’ll primarily need a utility knife or saw for cutting the boards, a tape measure, and possibly a staple gun for securing them in place. Safety glasses are also recommended.
Are there different densities of mineral wool insulation available?+
This product is offered with a standard density mineral wool. Higher density variants provide increased thermal performance but may be more difficult to handle. Consider your specific needs when selecting an option.
How should I prepare the surface before installing?+
Before installation, ensure the loft or wall cavity is clean and free from debris. Applying a bonding adhesive can improve adhesion and prevent slippage of the boards – check manufacturer recommendations for suitable adhesives.
What’s the typical lifespan of this type of insulation?+
Mineral wool insulation typically has a lifespan of 20-40 years when installed correctly, providing long-term thermal protection. Regular maintenance and checking for any damage will help extend its service life.