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.