Cellecta XROOF 300 120mm PIR Roof Insulation Board

The Cellecta Hexatherm XROOF 300L (120mm) is a high-performance extruded polystyrene XPS insulation board developed for inverted flat roof systems where strength, moisture resistance, and thermal efficiency are critical. Its closed-cell structure ensures long-term durability, making it suitable for residential, commercial, and industrial roofing applications across the UK.

Engineered to withstand heavy loads, this insulation board delivers dependable performance in demanding environments such as inverted roofs and landscaped or green roof builds.

Product Info

1. Product: Cellecta Hexatherm XROOF 300L
2. Thickness: 120mm
3. Width: 600mm
4. Length: 1250mm
5. Pack Size: 4 boards per pack
6. (In some UK regions, single board supply may be available on request—please enquire for delivery options.)
7. Coverage per Pack: 3.0 m²
8. Thermal Conductivity: 0.034 W/mK
9. Density: 34kg/m³
10. Type: Flat roof insulation board
11. Compressive Strength: 300kPa
12. Strength at 2% Compression: 125kPa
13. Water Absorption (long term immersion): 0.7%
14. Edge Profile: Shiplap

Key Details

1. High-strength XPS insulation designed for roofing applications
2. Ideal for inverted flat roof systems
3. Excellent thermal efficiency (0.034 W/mK conductivity)
4. High compressive strength of 300kPa for heavy-duty use
5. Minimal water absorption for enhanced longevity
6. Closed-cell structure for improved durability and insulation stability
7. Lightweight design for easier handling and installation
8. Fully recyclable material
9. CFC and HCFC free formulation
10. Low Global Warming Potential (GWP)
11. Zero Ozone Depletion Potential (ODP)
12. Suitable for sustainable building specifications and Code for Sustainable Homes compliance
13. Suitable Applications

The Cellecta Hexatherm XROOF 300L 120mm is commonly used in:

1. Inverted flat roofing systems
2. Green roof installations
3. Standard flat roof insulation
4. Pitched roof insulation layers
5. Commercial roofing projects
6. Industrial building roofs
7. Domestic roofing upgrades and new builds
8. Certifications & Standards
9. Manufactured to BS EN 13164 standards
10. Tested in accordance with BS EN 12267
11. CE marked for quality assurance
12. Compliant with the Code for Sustainable Homes requirements

Installation Guide

Please refer to the Downloads tab on this product page to access the official Cellecta HEXATHERM XROOF 300 datasheet and installation guide.

It contains the full manufacturer guidance, including:

1. Correct inverted roof installation method
2. Recommended roof build-up layers
3. Ballast requirements (gravel, paving slabs, or green roof systems)
4. Board layout and joint detailing
5. Compatibility with waterproofing membranes
6. Thermal performance and moisture resistance data
7. Compliance and certification details