35mm Unilin Thin-R PIR Insulation Board

Unilin Insulation (formerly Xtratherm)

35mm Unilin Thin-R Insulation Board (2400mm x 1200mm x 35mm) is a high-performance PIR rigid foil faced polyisocyanurate thermal foam solution suitable for multiple building applications including roofs, walls, floors, and timber or steel framed structures. With a certified thermal conductivity of just 0.022 W/mK, this ultra-thin board delivers excellent insulation performance.

About

35mm Unilin PIR boards are engineered for pitched roof insulation applications on ventilated, hybrid, or warm roof systems. The roof is a critical component of your building's thermal envelope and a major source of heat loss. Installing this PIR board minimises heat escape while maintaining excellent thermal bridging performance and maximising usable interior space. Designed for versatility across roofing, wall, and floor applications, this insulation is thin, lightweight, and straightforward to fit. The board offers fire resistance, water repellency, and a reduced environmental footprint.

Product Details

Thickness: 35mm

Length: 2400mm

Width: 1200mm

Overall Thickness Options: 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 60mm, 65mm, 70mm, 75mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 165mm

Maximum Board Weight: 0.45 kg/m²

Thermal Resistance: 1.59 m²K/W

Thermal Conductivity: 0.022 W/mK

Compressive Strength: >150 kPa

Water Vapour Resistivity: >100 MNs/gm

Density (Foam Core): 30–32 kg/m³

Surface Spread of Flame: Class 1

Reaction to Fire: E

Finish: Aluminium Foil Facings

Applications: Roofs, Walls, Floors, Timber & Steel Frame

ETA Notification: Yes

Features: Versatile ǀ High-performance ǀ Rigid

Warm roof insulation construction is particularly effective for complex roof designs. Positioning insulation above or between roof timbers maintains the structure at internal environmental conditions, reducing thermal stress and condensation problems.

Store 35mm PIR insulation boards on a clean, flat surface away from ground contact and under weatherproof cover. Polythene wrapping alone is insufficient for outdoor storage. Protect the boards during storage and construction. The insulation boards cut easily with a sharp knife or fine-toothed saw.

Key Facts

1. Unilin 35mm PIR achieves an A+ rating under the BRE Green Guide
2. Certified Lambda value of 0.022 W/mK
3. Minimal intrusion into living space
4. Condensation risk significantly reduced
5. Low emissivity foil facings
6. Lightweight and simple to install
7. Excellent thermal bridging performance
8. Suitable for ventilated roof systems
9. Suitable for warm roof systems
10. Suitable for hybrid roof systems

Explore our Unilin range and filter by thickness or coverage using the left-hand menu. For project-specific advice, quantity discounts, or a tailored quotation, contact us on +4402039519012, email sales@insulationbee.co.uk, or use our Live Chat service – competitive UK Insulation pricing.