SuperFOIL SF19BB Breathable Multifoil Insulation – 3-in-1 Breathable Solution

SuperFOIL SF19BB is a breathable multifoil insulation designed for applications where thermal performance, vapour permeability, and moisture control are critical. With a nominal thickness of 40 mm, SF19BB combines high-performance insulation, a reflective breathable membrane, and a radiant barrier in one advanced system.

Specifically engineered for roof and wall applications, SF19BB is ideal for new builds, retrofits, and timber-frame construction, as well as professional building projects where condensation risk must be carefully managed. The breathable membrane allows controlled vapour transfer while maintaining excellent thermal efficiency, supporting compliant and durable building envelope design.

For breathable systems such as SuperFOIL SF19BB, internal comparative assessments indicate that equivalent thermal performance varies according to product thickness and construction build-up and should be considered indicative only. As a reference within the SuperFOIL range, internal comparative assessments indicate that 65 mm of SuperFOIL SF40 can achieve thermal performance comparable to up to 450 mm of traditional mineral wool insulation (λ = 0.040 W/mK), depending on installation method, air gaps, and overall system design. Exact thermal performance must always be verified using the official SuperFOIL U-Value Calculator for the specific construction build-up,, supported by the certified R-Values of each product.

Product Dimensions & Coverage

• Thickness: 40 mm

• Length: 10 m

• Width: 1.5 m

• Coverage: 15 m² per roll

• Weight: 10 kg

3-in-1 Multifunctional Design

SuperFOIL SF19BB combines three essential functions in a single product:

• High-performance thermal insulation

• Reflective breathable membrane allowing moisture vapour to escape

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

This breathable design helps prevent the formation of mould and damp by reducing condensation risk while maintaining excellent thermal efficiency.

Thermal Performance

SF19BB works across conduction, convection, and radiation, while also allowing controlled vapour permeability — unlike standard vapour-closed multifoil insulation systems.

Certified thermal performance (core value + air spaces, EN 16012):

• Core R-Value: 1.45 m²K/W

• Roof (incl. air spaces): 2.03 m²K/W

• Wall (incl. air spaces): 2.24 m²K/W

• Floor (incl. air spaces): N/A

• Emittance: 0.19 / 0.05

Emittance (0.19 / 0.05) reflects the dual-layer design of SF19BB.

The breathable membrane side has a higher emittance value (0.19) to allow moisture vapour to pass safely through the construction, which is essential for breathable building systems.
The reflective foil side has a very low emittance value (0.05), providing the same high level of radiant heat reflection found in standard SuperFOIL multifoil insulation such as SF19+.

Although one surface is breathable rather than fully reflective, this does not reduce the overall thermal performance of the system. Instead, it allows SF19BB to combine effective insulation with moisture control, making it suitable for vapour-open roof and wall constructions where standard non-breathable products are not appropriate.

These values demonstrate SF19BB’s suitability for breathable roof and wall constructions where moisture control is essential.

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 and breathable membrane technology, SuperFOIL SF19BB delivers reliable thermal performance while allowing vapour to pass safely through the structure.

This makes it particularly effective in timber-frame and breathable wall or roof systems, where traditional insulation and non-breathable membranes may increase condensation risk.

Exact U-values depend on the full construction build-up. Bespoke U-value calculations are available for project-specific compliance.

Key Benefits

• Breathable multifoil insulation for roofs and walls

• Reduces condensation risk and helps prevent mould and damp

• Slim profile with strong thermal performance

• Replaces insulation, breathable membrane, and radiant barrier

• Easy to install – no specialist tools required

• Lightweight and flexible

• Minimal waste compared to traditional insulation systems

• Ideal for new builds and retrofits

• Rated W1 for watertightness, providing a secondary rain barrier

• Made from up to 40% recycled materials

• Fully recyclable with a 50+ year service life

Applications

SuperFOIL SF19BB is suitable for use in:

• Pitched roof constructions

• Wall systems

• Timber-frame constructions

It is typically installed as part of a breathable building envelope, allowing moisture vapour to escape while maintaining thermal efficiency.

Fire & Safety Performance

• Reaction to Fire (Euroclass): Class F

• Watertightness: W1 rating

SF19BB – Quality & Certification

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

• CE certified to EN 13859-1:2014 and EN 13859-2:2014 for breathable membrane 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 SF19BB?

SF19BB is specified in projects where breathability, moisture control, and thermal performance must work together. Its reflective breathable membrane supports healthy building envelopes, reduces condensation risk, and simplifies detailing in timber-frame and vapour-open constructions.

This makes SF19BB an excellent choice for architects, engineers, and contractors designing modern breathable roof and wall systems.

Compare the SuperFOIL Insulation Range

Summary

SuperFOIL SF19BB is a high-performance breathable multifoil insulation that combines insulation, moisture management, and radiant performance in a single integrated system. It supports healthy building envelopes, simplifies installation, and delivers long-term durability — making it an ideal solution for breathable roof and wall constructions in both professional and high-quality residential projects.