High Performance Floor Insulation

Effective floor insulation reduces heat loss, improves thermal comfort and supports long-term energy efficiency.

SuperFOIL multifoil systems are suitable for both solid and suspended timber floors, offering lightweight, space-efficient insulation with built-in vapour resistance. When properly specified, they help enhance building performance and support compliance with relevant building regulations.

SOLID FLOOR INSULATION

SYSTEM OVERVIEW – Solid Floor

Application Type:
Insulation to solid concrete slab floors

System Classification:
Low-profile multifoil floor insulation

Primary Function:
Thermal enhancement + Vapour resistance + Radiant barrier

Typical Product:
SuperFOIL SFUF

Product Thickness:
6 mm

Installation Method:
Typically direct application without required air gaps

Compression:
Minimal compression permitted

Finish:
Floating floor, timber floor system or screed-based finish (as per manufacturer guidance)

Solid floor SuperFOIL insulation - SFUF

provides a slim, high-performance solution where floor build-up depth is limited but vapour resistance and thermal enhancement remain important.

SuperFOIL SFUF differs from traditional multifoil systems. Due to its composition, it is typically installed without the need for reflective air gaps and allows minimal compression within the floor build-up.

Despite its low profile, it provides:

• Thermal enhancement
• Built-in vapour resistance (1200 MNs/g)
• Radiant barrier properties
• Minimal impact on finished floor height

Typical Build-Up Configuration

A typical solid floor build-up may include:

• Structural concrete slab
• Damp Proof Membrane (DPM)
• SuperFOIL SFUF
• Floating deck or internal floor finish

SFUF is typically installed:

• Directly over the slab or DPM
• With tightly butted joints
• With all joints sealed using SuperFOIL tape

Exact build-up configuration should be assessed according to project requirements and local building regulations.

Vapour Resistance & Moisture Considerations

With a vapour resistance of approximately 1200 MNs/g, SFUF provides inherent vapour control within the floor system.

However:

• The presence and condition of the DPM must be confirmed
• Moisture levels in the slab should be suitable before installation
• Full floor design should consider condensation behaviour where applicable

Project-specific assessment is recommended for refurbishment or hybrid floor systems.

Hybrid Solid Floor Configurations

SuperFOIL floor insulation may be used:

• As a standalone layer
• In single or duet configurations
• In combination with mineral wool
• In combination with PIR boards

When used in hybrid constructions, vapour balance and structural suitability should be assessed.

Typical Installation Principles

• Begin at one edge of the room
• Roll product out flat across the slab
• Butt joints tightly
• Seal all overlaps and joints using SuperFOIL tape
• Seal perimeter edges to maintain continuity

Floor finish should be installed in accordance with the flooring manufacturer’s recommendations.

---

SUSPENDED TIMBER FLOOR INSULATION

SYSTEM OVERVIEW – Suspended Timber Floor

Application Type:
Insulation to suspended timber joist floors

System Classification:
Multifoil insulation applied across joist structure

Primary Function:
Thermal insulation + Draught reduction + Vapour control + Radiant barrier

Installation Methods:
Direct application
Battened application

Staple Fixing (Typical):
Maximum 300 mm centres

Minimum Overlap:
50 mm

Airspace:
May be incorporated depending on installation method

Finish:
Internal flooring system

Introduction, Suspended Timber Floors

Installation Logic & Relation to Under Joist System

Suspended timber floor insulation follows similar structural principles to roof under joist systems.

This is because:

• Both systems involve timber joists
• Insulation is fixed across joists
• Airtight sealing is critical
• Airspace may be required depending on configuration

For this reason, typical installation detailing may follow principles similar to the Under Joist installation methodology.

However, floor constructions differ in thermal direction and ventilation behaviour and should be assessed accordingly.

Direct Application Method (Typical)

Installation may begin at the wall edge:

• Leave perimeter overlap folded up the wall
• Roll SuperFOIL across joists
• Maintain gentle tension while installing

Where an air cavity is required:

• Fix SuperFOIL to the side of the joist
• Position approximately 50 mm from the top of the joist
• Create consistent cavities across the floor

Fixing typically includes:

• Stapling into joists
• Staples spaced no greater than 300 mm centres
• Minimum 50 mm overlap between runs
• All joints sealed using 100 mm SuperFOIL tape

Trim at perimeter and seal to wall plate or adjoining insulation where present.

Proceed with internal flooring as per flooring manufacturer guidance.

Battened Application Method (Typical)

Alternatively, installation may include battens:

• Roll SuperFOIL across joists
• Keep product taut
• Staple securely into place
• Butt joints over joists
• Seal all joints, tears and penetrations

Install appropriately sized battens:

• Create required airspace (where specified)
• Prevent compression
• Provide secure fixing base for flooring

Batten sizing should correspond to product thickness.

Additional Insulation (Hybrid Floor Build-Up)

SuperFOIL may be combined with:

• Mineral wool between joists
• PIR boards

When installing insulation between joists:

• Ensure adequate joist depth
• Maintain any required subfloor ventilation
• Avoid blocking air bricks
• Consider condensation risk

Professional assessment is recommended for complex hybrid constructions.

Airspace & Performance

Where reflective airspace is part of the design:

• Maintain consistent cavity
• Avoid product compression
• Ensure airtight sealing

Without appropriate airspace, radiant heat transfer may convert to conductive heat, reducing reflective efficiency.

Airspace requirements should be determined according to selected product and build-up design.

Sealing & Airtightness

Proper sealing is critical.

Ensure:

• All overlaps taped
• All cut edges sealed
• Perimeter sealed to wall
• Service penetrations sealed

Effective sealing reduces:

• Draughts
• Air leakage
• Thermal bridging

Service Penetrations

For pipes, cables and ducting:

• Cut minimal opening
• Feed service through
• Seal using SuperFOIL tape

Copper pipes should be wrapped in non-metallic insulation before contact with aluminium foil.

All electrical work should comply with relevant regulations.

Cutting Methods

Recommended tools:

• Utility knife (compress insulation before cutting)
• Rotary cutter
• Heavy-duty shears

Seal all cut edges after trimming.

Installation Checklist – Suspended Floor

Before completion ensure:

• Product correctly tensioned
• Staples ≤ 300 mm centres
• Minimum 50 mm overlaps maintained
• All overlaps and cuts sealed
• Battens correctly sized (if used)
• Subfloor ventilation maintained
• Air bricks unobstructed

Recommended Products – Floor Applications

Solid Floor:

• SFUF (low-profile 6 mm solution)

Suspended Timber Floor:

• SF19+
• SF40
• SF60

Typical Floor Performance R-Values:

SF19+ → 4.29
SF40 → 5.23
SF60 → 6.24

Always verify required U-Value using the official SuperFOIL U-Value Calculator prior to specification.