Recticel Insulation Boards

Polyisocyanurate (PIR) insulation is a type of rigid foam insulation board backed with a foil layer, that is renowned for its exceptional thermal performance. It is a strong and light type of foam that keeps structures warm by trapping air inside. PIR insulation board is lightweight, durable, and offers excellent fire resistance and thermal insulating properties, making it a super DIY-friendly solution that can easily be cut to size to fit rafters to be used in roof insulation, between joists as loft insulation, within stud walls and used as Cavity Wall Insulation.

Our Recticel insulation boards all measure a standard size of - 2400mm x 1200mm, and are available in a variety of thicknesses to suit every size of floor, cavity or project such as:

25mm, 30mm, 40mm, 50mm, 60mm, 70mm, 75mm, 80mm, 90mm, 100mm, 120mm and 150mm.

The most popular sizes are 100mm Recticel, 50mm Recticel and 25mm Recticel. 

There are many different uses for PIR insulation board, so the method to install your Recticel insulation may vary. However, generally Recticel is intended to fit the depth of the cavity, such as when installing between joists as loft insulation, or Cut to fit the height and width required using a utility knife, or handsaw for thicker boards, to achieve a friction-fit  - meaning the boards should fit tightly and stay easily in place with no additional fixtures and fittings.

For precise installation instructions for your specific use case, it is recommended to consult your builder, architect or building inspector to ensure installation complies with building regulations. 

Recticel PIR insulation boards are rated Euroclass F Reaction to Fire classification, according to BS EN 13501-1

The R-Value of Recticel PIR Boards increases with the thickness of the board. The higher the R-Value, the greater the resistance of the board and therefore the more effective the thermal insulation. 

Recticel PIR boards have a thermal conductivity of 0.022 W/m.K.

R-Value (m².K/W)

• 25mm  - 1.10 
• 30mm - 1.35 
• 40mm - 1.80
• 50mm - 2.25
• 60mm - 2.70
• 70mm - 3.15
• 75mm - 3.40
• 80mm - 3.60
• 90mm - 4.05
• 100mm - 4.50
• 120mm - 5.45
• 150mm - 6.80

To calculate the U Value of your wall, you must consider the entire structure of the wall, including air gaps. A general formula for calculating the U-value:

U = 1 over R

Where:

U = U Value

R = The total thermal resistance of the building component, including all layers of materials and air gaps.

Recticel PIR boards have a thermal conductivity of 0.022 W/m.K.

Recticel boards are made of a closed-cell structure which means they do not specifically retain moisture, although they are not entirely waterproof.

Our extensive Recticel range delivers outstanding thermal conductivity of just 0.022 W/mK, meaning superior heat retention and significant energy savings for your property. These lightweight, foil-faced PIR boards combine decades of manufacturing expertise with cutting-edge sustainability—featuring zero ozone depletion potential and minimal global warming impact.

Popular applications include:

• Pitched roof insulation between rafters
• Floor insulation beneath joists
• Internal wall cavity filling
• Loft insulation projects
• Flat roof constructions with PowerDeck systems

Complete Product Range Available

From our Stapleford warehouse, we supply the full spectrum of Recticel solutions:

Eurothane General Purpose Boards (2400mm x 1200mm) in thicknesses from 25mm to 150mm—perfect for versatile building applications where space and performance matter.

PowerDeck Flat Roof Systems featuring enhanced compressive strength for demanding commercial and residential flat roof projects.

Eurowall Cavity Insulation with precision-engineered tongue and groove joints, eliminating thermal bridging in masonry applications.

Expert Support When It Matters

Unlike typical merchants, our experienced team understands that choosing the right insulation thickness affects both building regulations compliance and long-term energy costs. We'll help calculate your specific U-value requirements and recommend the optimal Recticel specification for your project's unique demands.

Ready to specify the right Recticel Insulation Boards? Our building materials experts are standing by to provide technical guidance and competitive pricing across our complete range. Contact us today for professional advice that ensures your project's thermal performance exceeds expectations.