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.
#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
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.
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.