SuperFOIL SF40BB Breathable Multi-Layered Foil Insulation – 10m x 1.5m

SuperFOIL SF40BB Breathable Multi-Layered Foil Insulation is a high-performance breathable multifoil insulation that combines thermal insulation and a breathable membrane within a single product. Designed primarily for roofing and external cladding applications, SF40BB can replace the need to install separate insulation and breather membrane layers in suitable constructions.

The outer layer incorporates a reflective breathable membrane designed to act as a secondary rain barrier while allowing water vapour to escape. The insulation layers beneath are perforated so that breathability is maintained throughout the complete product.

With a stated core thermal resistance of 2.92 m²K/W, low water vapour resistance of just 0.115 MNs/g and W1 resistance to water penetration, SuperFOIL SF40BB provides an effective combination of thermal insulation, moisture management and reflective radiant barrier performance.

Each roll measures 1.5m x 10m, providing 15m² of coverage at a nominal thickness of 79mm.

What is SuperFOIL SF40BB Used For?

SuperFOIL SF40BB is designed particularly for applications requiring both thermal insulation and a breathable external membrane.

Typical applications include:

• Pitched roof insulation
• Roofing projects
• External cladding systems
• Timber frame construction
• New-build properties
• Extensions
• Renovation projects
• Refurbishment projects
• Retrofit insulation
• Hybrid insulation systems
• Residential construction
• Suitable commercial buildings

Its 2-in-1 construction can simplify roof and external wall build-ups by combining two normally separate installation stages.

2-in-1 Breather Membrane and Insulation

One of the primary advantages of SuperFOIL SF40BB is its 2-in-1 construction.

Rather than installing separate layers of thermal insulation and breathable membrane, SF40BB combines both functions within one product.

This can provide several practical advantages:

• Fewer separate materials to purchase
• Fewer installation stages
• Reduced installation time
• Simplified construction build-up
• Reduced material handling
• Potential labour savings
• Less opportunity for gaps between separate insulation layers

This makes SF40BB particularly useful for roof and external cladding projects where both insulation and breathability are required.

High-Performance Breathable Multifoil Insulation

SuperFOIL SF40BB has been specifically developed as a breathable multifoil insulation.

A reflective breathable membrane forms the outer layer of the product, while the insulation layers beneath are perforated.

These perforations allow water vapour to pass through the complete insulation rather than becoming trapped between individual layers.

This provides the thermal benefits associated with multifoil insulation while maintaining the vapour permeability required on the breathable side of an appropriately designed building envelope.

2.92 m²K/W Core Thermal Resistance

SuperFOIL SF40BB provides a stated core thermal resistance of 2.92 m²K/W.

This substantial thermal resistance allows SF40BB to contribute significantly towards the overall insulation performance of a roof or wall construction.

Additional performance may be achieved within the complete construction depending on factors including:

• Adjacent airspaces
• Other insulation products
• Structural materials
• Internal finishes
• External finishes
• Installation configuration
• Thermal bridging

The final U-value should therefore be calculated using the complete building element rather than the SF40BB core performance alone.

Highly Breathable Construction

SuperFOIL SF40BB provides a very low stated water vapour resistance of 0.115 MNs/g.

This allows water vapour to pass readily through the product and escape towards the exterior of an appropriately designed construction.

High vapour permeability is particularly important within roof and external wall systems, where moisture that enters the building fabric needs a route to escape.

Allowing water vapour to disperse can help reduce the risk of moisture accumulating within the insulation and surrounding building materials.

Helps Reduce the Risk of Condensation

Moisture generated within occupied buildings can migrate into roofs and walls.

If this moisture reaches colder areas of the construction and cannot escape, interstitial condensation can occur.

The highly breathable construction of SuperFOIL SF40BB allows water vapour to pass through the insulation towards the exterior.

When incorporated into an appropriately designed roof or wall system, this can help reduce the risk of condensation accumulating within the building fabric.

Reflective Breathable Outer Membrane

The external layer of SuperFOIL SF40BB is a reflective breathable membrane.

This layer provides several functions within the complete product:

• Breathable membrane
• Secondary rain barrier
• Reflective surface
• Low-emissivity radiant barrier
• Protective outer layer

Combining these properties within the outer surface allows SF40BB to provide both moisture-management and thermal benefits.

W1 Resistance to Water Penetration

SuperFOIL SF40BB achieves a stated W1 resistance to water penetration.

This allows its outer breathable membrane to act as a secondary rain barrier within appropriate roof and wall constructions.

The combination of W1 water resistance and 0.115 MNs/g vapour resistance means SF40BB can resist external water penetration while still allowing internal water vapour to escape.

Secondary Rain Barrier

Within suitable roofing and external cladding applications, the breathable outer membrane provides a secondary barrier against rainwater that penetrates beyond the primary roof covering or cladding.

This helps protect the insulation and underlying construction from external moisture.

The primary roof covering or cladding should still provide the principal weatherproof layer of the building envelope.

Reflective Radiant Barrier

In addition to its core insulation performance, SuperFOIL SF40BB incorporates reflective surfaces that can help reduce radiant heat transfer.

When a reflective surface faces an appropriate airspace, it creates a low-emissivity environment that reduces the transfer of heat through thermal radiation.

This allows SF40BB to address several forms of heat transfer within one insulation system.

Warmer in Winter

During colder weather, SuperFOIL SF40BB helps reduce heat transfer through its multi-layer insulation construction.

Its reflective radiant barrier properties can provide additional benefits where suitable airspaces are incorporated into the construction.

This helps reduce heat loss through the building envelope and contributes towards maintaining a warmer internal environment.

Cooler in Summer

Reflective insulation can also provide benefits during warmer summer conditions.

The reflective surfaces help reduce radiant heat transfer and can contribute towards reducing unwanted solar heat gain through suitable roof and external wall constructions.

This provides useful year-round thermal performance, helping buildings remain warmer in winter and cooler in summer.

Ideal for Roofing Applications

SuperFOIL SF40BB is particularly suited to roof insulation projects because it combines thermal insulation with the breathable membrane normally required towards the external side of the construction.

Potential applications include:

• New-build pitched roofs
• Roof extensions
• Loft conversions
• Roof renovations
• Retrofit roof insulation
• Complete roof refurbishment
• Hybrid roof insulation systems

Its combined functionality can simplify roof build-ups while maintaining the breathability required by the overall construction.

Ideal for External Cladding

SF40BB can also be incorporated into appropriate external cladding systems.

The breathable outer layer allows moisture vapour to escape while providing W1 resistance to external water penetration.

This combination makes the product particularly useful where insulation and a breathable secondary weather-resistant layer are both required behind suitable external cladding.

79mm Thick Multifoil Insulation

SuperFOIL SF40BB has a nominal installed thickness of 79mm.

Its multi-layer construction provides a stated core R-value of 2.92 m²K/W, combining substantial thermal resistance with breathable and reflective properties.

This can make SF40BB particularly useful where a high-performance insulation layer is required within a relatively compact roof or wall construction.

Can Be Used with Other Insulation

SuperFOIL SF40BB can be combined with other suitable insulation products to create hybrid insulation systems.

This allows its thermal, breathable and reflective properties to complement conventional insulation materials.

Potential combinations can include suitable:

• Rigid insulation boards
• Mineral wool
• Glass wool
• Other breathable insulation products
• Other compatible insulation systems

The final U-value should be calculated using the complete construction.

Can Be Used in Multiple Layers

Where appropriate to the construction design, SuperFOIL SF40BB can also be incorporated into multi-layer insulation systems.

This provides additional flexibility when designing roofs and walls to achieve particular thermal targets.

Care should be taken to ensure that the complete construction maintains the required moisture-management characteristics and that vapour resistance is appropriately arranged throughout the building element.

Helps Improve Airtightness

A continuous multifoil insulation installation can help reduce unwanted air movement through the building envelope.

Controlling air leakage is an important part of improving building energy efficiency because draughts and uncontrolled air movement can increase heat loss through convection.

SF40BB can contribute towards improved insulation continuity and reduced unwanted air movement when correctly installed and detailed.

Its breathable nature should not be confused with uncontrolled air leakage. A membrane can allow water vapour diffusion while still contributing towards an appropriately detailed building envelope.

Strong and Durable Construction

SuperFOIL SF40BB provides good mechanical strength for normal handling and installation.

Its stated tensile properties are:

• Length: 238 / 227 N/50mm
• Width: 111 / 100 N/50mm

Its stated resistance to tearing is:

• Length: 179N
• Width: 179N

The stated elongation properties are:

• Length: 61 / 57%
• Width: 92 / 87%

These characteristics provide useful durability and flexibility when installing the product across roof and external wall constructions.

Flexible at Low Temperatures

SuperFOIL SF40BB has a stated low-temperature flexibility of -40°C.

This helps the material retain flexibility across a wide range of temperatures, an important characteristic for insulation and breathable membranes incorporated towards the external side of the building envelope.

Manufactured Using 40% Recycled Materials

SuperFOIL SF40BB is manufactured using approximately 40% recycled materials.

This allows recycled material content to be incorporated into the insulation system while maintaining the thermal, breathable and mechanical performance required for suitable construction applications.

15m² Coverage Per Roll

Each SuperFOIL SF40BB roll measures:

1.5m wide x 10m long

This provides a total nominal coverage of:

15m² per roll

Each roll weighs approximately 20kg and has a nominal thickness of 79mm.

The 1.5m width provides substantial coverage with each run, helping simplify installation across larger roof and wall areas.

Independently Tested Performance

SuperFOIL insulation products are independently tested by third-party certified laboratories and notified bodies to establish their performance characteristics.

The manufacturer states that its insulation products are tested for use as part of constructions designed to meet relevant UK Building Regulations and applicable UK and European requirements, including CE requirements.

Thermal performance testing is carried out using recognised methods applicable to insulation products, including those referenced by BR443 and Part L.

Project-specific suitability should always be assessed against the thermal, moisture, structural, fire and regulatory requirements of the complete construction.

Key Features and Benefits

• High-performance breathable multifoil: Combines insulation and breathability within one product
• 2-in-1 construction: Breather membrane and insulation layer in one
• 2.92 m²K/W core R-value: Provides substantial core thermal resistance
• Highly breathable: Very low water vapour resistance of 0.115 MNs/g
• Helps reduce condensation risk: Allows water vapour to escape from the construction
• W1 water resistance: Provides excellent resistance to water penetration
• Secondary rain barrier: Reflective breathable outer membrane provides additional weather protection
• Reflective radiant barrier: Helps reduce radiant heat transfer
• Winter performance: Helps reduce heat loss
• Summer performance: Helps reduce radiant heat gain
• Ideal for roofing: Designed for appropriate pitched roof insulation systems
• Ideal for external cladding: Suitable for appropriate external wall and cladding constructions
• New-build applications: Suitable for appropriate new construction
• Extension projects: Combines two installation stages into one
• Renovation applications: Suitable for refurbishment and thermal upgrades
• Hybrid insulation compatible: Can be combined with other suitable insulation materials
• Multiple layer installation: Can be incorporated into appropriately designed multi-layer systems
• 79mm thickness: High-performance multi-layer construction
• 15m² coverage: Each 1.5m x 10m roll provides substantial coverage
• 20kg roll weight: Manageable roll format for site installation
• Strong construction: Good tensile and tear resistance
• Low-temperature flexibility: Flexible down to -40°C
• 40% recycled materials: Manufactured using recycled content
• Reduced installation stages: Eliminates the need for separate insulation and breather membrane layers in suitable constructions
• Minimal waste: Flexible roll format allows efficient cutting and installation
• Independently tested: Performance assessed by recognised laboratories and notified bodies

SuperFOIL SF40BB Breathable Multi-Layered Foil Insulation Specification

Why Choose SuperFOIL SF40BB Breathable Multi-Layered Foil Insulation?

SuperFOIL SF40BB Breathable Multi-Layered Foil Insulation provides a high-performance 2-in-1 insulation and breather membrane solution for suitable roofing and external cladding projects.

Its stated 2.92 m²K/W core thermal resistance provides substantial insulation performance, while the extremely low 0.115 MNs/g water vapour resistance allows moisture vapour to escape readily through the complete product. At the same time, its W1 resistance to water penetration allows the reflective outer membrane to function as a secondary rain barrier.

By combining insulation and a breathable membrane within a single product, SF40BB can eliminate a separate installation stage in suitable constructions, potentially reducing labour, installation time and the quantity of individual materials required.

Its reflective surfaces also provide radiant barrier performance, helping reduce heat loss during winter and radiant heat gain during summer.

With a nominal thickness of 79mm, approximately 40% recycled material content and 15m² coverage per 1.5m x 10m roll, SuperFOIL SF40BB provides a versatile solution for projects requiring breathable multifoil insulation, reflective roof insulation or combined insulation and breather membrane performance.