40mm Unilin FR/ALU Flat Roof Insulation Board

40mm Unilin FR/ALU, previously known as 40mm Xtratherm FR/ALU, delivers premium-grade Polyisocyanurate flat roof insulation with dual vapor-tight aluminium foil facings, engineered for compatibility with single-ply membranes. This product forms part of Unilin's comprehensive range of high-performance flat roof boards, delivering integrated solutions for flat roof applications.

Product specification

Brand: Unilin Insulation FR/ALU (formerly Xtratherm FR/ALU)

Model: 40mm Unilin FR/ALU

Thickness: 40mm

Available Thicknesses: 25mm, 30mm, 40mm, 50mm, 60mm, 70mm, 75mm, 80mm, 90mm, 100mm, 110mm, 120mm, 125mm, 130mm, 140mm, 150mm

Length: 2400mm

Width: 1200mm

Board Coverage: 2.88m²

Pack Coverage: 20.16m²

Pack Quantity: 7 sheets

Pack Weight: 28kg

Dimensions: 2,400mm x 1,200mm x 40mm

Thermal Conductivity: 0.022 W/mK

R-Value: 1.80 m²K/W

Colour: Light yellow

Density: 32 Kg/m³

Compressive Strength: > 150kPa

Material: Polyisocyanurate Rigid Foam (PIR insulation board)

Profile: Square Edge

Fire Reaction: Euroclass B, s2-d0

Finish: Vapour resistant gas-tight foil

Inner Facing: Foil Facing

Outer Facing: Foil Facing

Applications: Flat Roof Waterproofing Systems

BBA Certified: Yes (No. 11/4817)

Fixing Method: Mechanically fixed single ply waterproofing systems

Foil Faced: Yes, gas-tight foil facings on both sides

Features: Composite gas-tight foil facings on both sides

Manufacturer: Unilin Insulation®

Main Highlights:

1. Outstanding thermal performance and efficiency
2. Dual foil facers delivering superior vapour control
3. Ideal for mechanically fixed single-ply applications
4. Environmental Product Declaration (EPD) certified by IGBC – contact our technical team for further details

Advantages:

1. Outstanding thermal performance and efficiency
2. Works seamlessly with mechanically fixed single-ply and loose-laid ballasted systems
3. Superior vapour control through foil facers
4. Backed by an Environmental Product Declaration (EPD) certified by IGBC – reach out to our technical support for comprehensive information

About

The 40mm Unilin FR/ALU Flat Roof Insulation Board combines rigid polyisocyanurate PIR insulation with gas-tight foil facings on both surfaces.

Engineered for thermal insulation and slope creation on restricted-access concrete, timber, or metal flat roof decks in new and refurbished buildings, this 40mm board serves dual functionality.

When paired with a vapour control layer and a mechanically fixed single-ply roof waterproofing membrane, the 40mm Unilin FR/ALU performs optimally.

Installation requires laying boards over the vapour control layer in a break-bonded arrangement for maximum coverage.

Secure the 40mm Unilin insulation boards with approved mechanical fixings to guarantee stability.

Roof Design

Reference BS 4841: Part 3 and Single Ply Roofing Association guidelines when planning your roof structure.

Falls

Flat roofs require consistent, adequate fall gradients to prevent water pooling and ensure proper drainage.

Fire Performance

Fire classification, determined by EN 13501-5 and BS 476 Part 3 'External Fire Exposure Roof Test', depends on the waterproofing system selected.

Note: This board was previously marketed as 40mm Xtratherm Thin-R FR/ALU Flat Roof PIR Insulation Board

Info

Browse our complete Unilin collection and refine by thickness or coverage using the left-hand filters. For project-specific advice or bulk quotations, contact us on +4402038839057, email sales@insulationbee.co.uk or use Live Chat – competitive UK Roof Insulation Board pricing.