Best Loft & Wall Insulation — Multifoil (2026)
2 loft & wall insulation matching material “Multifoil”, hand-picked from UK Amazon listings.
Not sure which one to pick? Read our Best Loft & Wall Insulation UK (2026) guide.
Multifoil loft and wall insulation provides a highly effective solution for thermal protection within your home’s attic or walls. This foil-faced mineral wool product combines the superior insulating properties of natural mineral wool with a reflective foil backing, creating a dual action system designed to reduce heat loss in winter and keep your property cooler during summer months. The mineral wool component absorbs radiant heat, while the foil layer reflects it back, maximising efficiency and minimising energy bills.
This multifoil insulation is ideal for use in lofts, external walls, and internal party walls where space is a premium. It's easily installed around obstructions and offers excellent thermal performance compared to traditional foil-only options. The mineral wool also helps to reduce sound transmission, contributing to a quieter home environment.
When selecting multifoil loft insulation, consider the R-value – this indicates the material’s resistance to heat flow. Higher R-values mean greater thermal efficiency and can significantly impact your energy savings. Ensure you measure your loft or wall cavity accurately before purchasing to guarantee correct coverage and optimal performance.
#1 Pick
SuperFOIL SF6 Multifoil Insulation 1.2m x 10m - Energy Saving DIY Multifoil Insulation Roll - 3-in-1 Sustainable Thermal Insulation Reflective Radiant Barrier & Vapour Barrier- Multifoil
- 1.2m x 10m
£84.99
Pros
- Thin multifoil roll saves space versus bulky mineral wool in tight lofts
- 3-in-1 design combines insulation, radiant barrier and vapour barrier
- Lightweight roll is easy for one person to install solo
Cons
- Needs an air gap either side to perform as rated, adding install complexity
#2 Pick
SuperFOIL SF19+ Multifoil Insulation 1.2m x 10m | High-Performance Thermal Roll for Loft, Roof, Wall & Floor- Multifoil
- 1.2m x 10m
£109.99
Pros
- 3-in-1 multifoil combines thermal insulation, vapour barrier and radiant foil in one roll
- Slim profile saves internal space versus thick mineral wool builds
- Suits loft, roof, wall and floor applications from a single product
Cons
- Needs taped, sealed laps to perform properly, so installation is fiddlier than a simple roll
FAQ
What is the typical R-value of multifoil loft insulation?+
Multifoil loft insulation typically offers an R-value between 3.0 and 4.0 per layer, depending on the density of the mineral wool. Always check the product specifications for the exact R-value stated by the manufacturer before purchasing.
How does multifoil insulation compare to single foil insulation?+
Multifoil insulation is superior as it combines the insulating properties of mineral wool with the reflective qualities of foil. Single foil insulation lacks this crucial thermal absorption, making multifoil a more effective and efficient choice for reducing heat loss.
Can I cut multifoil insulation to fit awkward spaces?+
Yes, you can easily cut multifoil insulation using a sharp utility knife or scissors. However, it’s recommended to use a straight edge to ensure accurate cuts and maintain the foil's reflective performance – avoid stretching the foil during cutting.
What tools do I need to install multifoil loft insulation?+
You’ll typically need a staple gun (or a hand staple tool), a utility knife, measuring tape, gloves, and safety glasses for installing multifoil loft insulation. A ladder is essential for accessing your loft space.
How much multifoil insulation do I need for my loft?+
Calculate the volume of your loft space (length x width x height) and then divide by 10 to determine the required area in square metres. Multiply this area by the desired R-value to calculate the total insulation needed, considering the product’s coverage per roll.
Is multifoil insulation suitable for damp lofts?+
While multifoil insulation can be used in moderately damp lofts, it's crucial to ensure the mineral wool component is treated with a moisture-resistant additive. Check the manufacturer's specifications for suitability and consider adding a breathable vapour barrier if necessary.
How does multifoil insulation affect condensation?+
The reflective foil backing of multifoil insulation helps reduce surface temperatures, minimising the risk of condensation forming on the interior walls or loft surfaces – this is particularly beneficial in cooler climates.
What’s the best way to secure the foil backing?+
Use a staple gun with appropriate staples designed for mineral wool to securely attach the foil backing to the framing. Ensure staples are spaced evenly and don't overlap, which can reduce the reflective performance of the foil.
Can I install multifoil insulation in external walls?+
Yes, multifoil insulation is suitable for use in external walls, but it’s vital to ensure a breathable cavity wall construction. Correct installation with adequate ventilation is key to prevent moisture build-up behind the insulation.
What does the ‘coverage per roll’ mean on the packaging?+
The coverage per roll refers to the square metres of loft or wall space that one roll of multifoil insulation will cover when installed according to the manufacturer's recommendations. This value is crucial for calculating your total material requirements.