UnderPlate® UFH Aluminium Spreader Plate – 1000mm x 200mm x 0.5mm

The UnderPlate® Aluminium Spreader Plate is a specialist underfloor heating solution designed for installation from beneath suspended timber floors, making it ideal for retrofit projects where the existing floor finish is already in place. Each 0.5 mm aluminium plate features pre-formed grooves to hold 16mm UFH pipework securely, ensuring fast, even heat distribution with minimal disruption to the existing structure.

Before installation, the joist void must be well insulated – typically with 100mm of mineral wool insulation – to maximise heat output and minimise downward losses. Plates are fixed directly to the underside of the floor deck using 3-4 screws per plate (ensuring the screw length does not penetrate the floor above). The system is designed for straight pipe runs and typically covers around 60% of the heated floor area.

Once the pipework is pressed into the diffuser plates, the reflective aluminium surface efficiently transfers heat upwards through the subfloor layers, achieving an impressive heat output of up to 70 W/m² when correctly installed. Compact, efficient and installer-friendly, the UnderPlate system provides a dependable heating solution for both renovation and retrofit applications.

Key Features:

• Under-Joist Installation – Ideal for retrofit floors with existing finishes
• High-Conductivity Aluminium – Fast and even heat distribution
• Pre-Formed Pipe Channels – Secure 16mm UFH pipe positioning
• Energy-Efficient Design – Up to 70 W/m² output with correct insulation
• Simple Installation – Fix from below using standard screws (3-4 per plate)

Why choose OverPlate?

UnderPlate offers a practical and efficient solution for underfloor heating installations where the floor finish cannot be removed. Designed for simple under-joist fitting, it delivers reliable heat transfer and consistent performance without major disruption. With high-quality aluminium diffuser plates, secure pipe channels and excellent thermal efficiency, UnderPlate provides a proven retrofit heating system that combines ease of installation with lasting comfort.

Part of our range of Timber Joisted Underfloor Heating

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