Cellecta HEXATHERM XDRAiN 50mm XPS Roof Insulation Board

The 50mm HEXATHERM XDRAiN is a high-performance extruded polystyrene XPS insulation board specially developed for use within inverted roof systems. Manufactured using CO₂ blowing technology, this lightweight yet durable insulation board delivers excellent thermal efficiency, superior moisture resistance and outstanding compressive strength, making it ideal for demanding flat roofing environments.

Unlike conventional XPS insulation boards, HEXATHERM XDRAiN incorporates a unique moulded drainage channel design on the underside of each board. These integrated channels allow rainwater to flow freely beneath the insulation layer, regardless of the board installation direction. This innovative design removes the need for a separate drainage membrane in many inverted roof constructions, helping to simplify installation and reduce overall roof build-up.

Suitable for a wide range of applications including green roofs, roof terraces, balconies and protected flat roofs, the 50mm HEXATHERM XDRAiN board provides long-lasting thermal performance while resisting water ingress and maintaining its insulating properties over time.

HEXATHERM XDRAiN Technical Specification

1. Product: 50mm HEXATHERM XDRAiN XPS Insulation Board
2. Material: CO₂ blown extruded polystyrene (XPS)
3. Board Size: 1250mm x 600mm
4. Board Coverage: 0.75m²
5. Boards Per Pack: 8
6. Pack Coverage: 6m²
7. Density: 34kg/m³
8. Weight Per m²: 1.7kg
9. Board Weight: 1.28kg
10. Thermal Conductivity (λ): 0.033 W/mK (up to 80mm thickness), 0.034 W/mK (81mm and above)
11. Thermal Resistance (R-Value): 1.52m²K/W
12. Compressive Strength: 300kPa
13. Compressive Stress at 2% Compression: 125kPa
14. Edge Detail: Shiplap edge profile
15. Long-Term Water Absorption by Immersion: 0.7%

Key Benefits of 50mm HEXATHERM XDRAiN

• Specifically designed for inverted flat roof systems
• Built-in drainage channels eliminate the need for a separate drainage layer in many applications
• Excellent choice for green roofs, terraces, podium decks and flat roofs
• High compressive strength suitable for areas subjected to regular loads
• Low water absorption helps preserve thermal performance throughout its service life
• Lightweight boards for easier handling and installation
• Shiplap edges help reduce thermal bridging and improve board stability
• Durable XPS construction with long-term insulation performance

50mm HEXATHERM XDRAiN Installation Instructions

1. Roof Deck Preparation Before installation, ensure the roof deck is structurally sound, clean and free from dust, debris or standing water. The waterproof membrane should be fully installed, inspected and tested to confirm it provides a complete watertight barrier.

2. Installing the XPS Insulation Boards Lay the 50mm HEXATHERM XDRAiN insulation boards directly over the waterproofing membrane. The underside drainage channels are designed to function effectively in any direction, allowing installers greater flexibility while ensuring efficient water movement beneath the insulation layer.

3. Completing the Roof Build-Up The remaining roof layers should be installed according to the specified roof design. For green roof systems, this may include a root barrier, filtration layers, additional drainage components where required, growing medium and vegetation.

4. Ballasting and Surface Protection Once the insulation has been installed, apply the specified ballast, paving system, gravel layer or green roof construction to secure the boards against wind uplift and provide protection from external traffic and loading.

5. Inspection and Maintenance After installation, check that all boards are laid tightly together, drainage channels remain clear and all layers of the roof system have been installed correctly. Regular roof inspections are recommended to maintain effective drainage performance.

Important Installation Information

50mm HEXATHERM XDRAiN insulation boards should always be installed in accordance with the project specification, current UK Building Regulations, relevant British Standards and the manufacturer’s latest installation recommendations. Roof designs should be assessed to ensure the selected insulation thickness achieves the required thermal performance and load-bearing requirements.