SuperFOIL SF40 Multifoil Insulation – High-Performance 3-in-1 Solution

SuperFOIL SF40 is a high-performance multifoil insulation designed for modern construction, renovations, and energy-efficient retrofits. With a slim profile of just 65 mm, SF40 combines thermal insulation, a radiant barrier, and an integrated vapour control layer (VCL) in one advanced system – reducing build-up depth while delivering outstanding thermal performance.

Engineered using multi-layer reflective technology and high-performance wadding, SF40 provides reliable, tested performance for roofs, walls, and floors, making it a versatile solution for both residential and commercial projects.

This is a vapour-closed multifoil insulation with an integrated vapour control layer (VCL), designed for internal applications where airtightness and condensation control are required.

Equivalent thermal performance in typical construction build-ups: internal comparative assessments indicate that 65 mm of SuperFOIL SF40 can achieve thermal performance comparable up to 450 mm of traditional mineral wool insulation (λ = 0.040 W/mK), depending on installation method, air gaps, and overall system design. These values are provided for indicative comparison purposes only. Final thermal performance must always be verified using the official SuperFOIL U-Value calculation for the specific construction build-up, supported by the certified R-Values of each product.

Product Dimensions & Coverage

• Thickness: 65 mm

• Length: 10 m

• Width: 1.5 m

• Coverage: 15 m² per roll

• Weight: approx. 15 kg

3-in-1 Multifunctional Design

SuperFOIL SF40 performs three essential functions in a single product:

• High-performance thermal insulation

• Radiant barrier – reflects radiant heat back into the building during winter and reduces solar heat gain in summer

• Vapour control layer (VCL) – eliminates the need for a separate vapour barrier

This integrated design simplifies construction, reduces material layers, and helps achieve target U-values efficiently.

Thermal Performance

SF40 works on all three modes of heat transfer – conduction, convection, and radiation – unlike traditional insulation materials that mainly address conduction.

Certified thermal performance (EN 16012):

• Core R-Value: 2.57 m²K/W

• Roof (incl. air spaces): 3.47 m²K/W

• Wall (incl. air spaces): 3.90 m²K/W

• Floor (incl. air spaces): 5.23 m²K/W

• Emittance: 0.05

Thanks to its reflective foil layers and integrated air spaces, SF40 delivers high thermal efficiency with minimal thickness.

What does R-Value mean?

R-Value (m²K/W) measures a material’s resistance to heat flow.
The higher the R-Value, the better the insulation performance.

What does Emittance mean?

Emittance measures how much heat a surface emits (radiates).

A low emittance value (typically around 0.05) means very low heat emission and high reflection of radiant heat, improving overall thermal performance when installed with adjacent air spaces.

This interpretation is aligned with EN 16012 and reflects how reflective multifoil insulation performance is evaluated across EU technical documentation.

Performance vs. Traditional Insulation

Thanks to its multi-layer reflective construction, SuperFOIL SF40 can achieve U-values typically associated with much thicker traditional insulation systems.

In practical build-ups, a 65 mm layer of SF40 can deliver thermal performance comparable to significantly thicker mineral wool or glass wool systems, depending on the overall construction and air space configuration. This allows designers and installers to reduce build-up depth, gain usable internal space, and simplify detailing – especially in projects where space is limited.

Exact U-values depend on the full construction build-up. Bespoke calculations are available for compliance and building control approval.

Key Benefits

• Slim profile – only 65 mm thick

• Replaces multiple layers (insulation + VCL + radiant barrier)

• Fast and easy installation – no specialist tools required

• Minimal waste compared to rigid boards or thick quilts

• Suitable for new builds and retrofits

• Can be combined with other insulation types

• Improves airtightness and reduces condensation risk

• Durable with a long service life, 50+ years

• Made using up to 40% recycled materials

Applications

SuperFOIL SF40 is suitable for use in:

• Pitched and flat roofs

• Internal wall systems

• Timber frame and solid wall constructions

• Floor structures

Typically installed on the internal side of the building envelope as part of dry-lining systems.

Fire & Safety Performance

• Reaction to Fire (Euroclass): Class F

• Water vapour resistance: 2,500 MNs/g

• Resistance to water penetration: W1

SF40 - Quality & Certification

• Manufactured under a certified ISO 9001:2015 quality management system

• CE certified to EN 13984:2013 for vapour control performance

• Tested to meet current UK and EU building regulations when installed correctly

• Designed, tested, and supported by SuperFOIL technical specialists

• Independently tested and assessed as part of the SuperFOIL multifoil insulation range, including
  BBA testing (British Board of Agrément – independent product and system performance assessment)
  and LABC certification (Local Authority Building Control – approval for compliance with building regulations)
  at range level

Why Choose SuperFOIL SF40?

SF40 is widely specified in projects where high thermal performance, limited build-up depth, and regulatory compliance are critical. Its slim design enables architects, engineers, and contractors to meet demanding U-value targets without sacrificing space, while simplifying installation and reducing overall system complexity.

Bespoke U-value calculations, condensation risk analysis, and technical support are available for project-specific requirements.

Compare the SuperFOIL Insulation Range

Summary

SuperFOIL SF40 is a high-performance, space-saving insulation solution that replaces multiple traditional layers with one smart system. It delivers excellent thermal efficiency, simplifies installation, and supports modern energy-efficient building design – making it an ideal choice for both professional contractors and demanding homeowners.