UnderPlate®
Suspended System
UnderPlate®
UnderPlate® is a retrofit‑ready UFH solution designed specifically for installation from beneath an existing floor, making it ideal when the finished flooring cannot be removed. The system uses lightweight aluminium diffuser plates fixed directly to the underside of the floor deck, enabling efficient heat transfer upward through the structure without altering floor height or requiring disruptive refurbishment.
As with all plated systems, the joist void must be properly insulated, typically with 100mm mineral wool, to ensure heat is directed upwards rather than lost below. Once secured, each aluminium plate supports straight pipe runs and provides approximately 60% coverage of the heated floor area, allowing the pipework to be installed from underneath without disturbing the room above.
UnderPlate® is tested in accordance with BS EN 1264‑2:2021, delivering responsive, efficient heat output through its reflective aluminium diffuser plates, which maximise upward heat transfer and improve system responsiveness in suspended timber floor constructions.
Why Choose UnderPlate®?
- Retrofit‑Friendly Installation: Fit UFH from below the floor, perfect for upgrades where flooring cannot be lifted.
- High Efficiency Aluminium Plates: Reflective diffuser plates deliver up to 70 W/m² at 45°C MWT and 0 tog covering.
- Zero Floor Build‑Up: All components sit beneath the floor deck, maintaining existing room heights.
- Fast Thermal Response: Aluminium plates distribute heat evenly and speed up warm‑up times.
- Lightweight System: Easy handling and straightforward installation within timber joist voids.
System Components & Build‑Up
- Timber floor deck (existing)
- Suspended timber floor joists
- Aluminium diffuser spreader plates (1000mm x 200m x 0.5mm)
- 16mm Ambiente UFH pipe installed into plates
- Minimum 100mm mineral wool insulation within the joist void
This configuration ensures efficient upward heat transfer and excellent performance within retrofit suspended floor structures.
Thermal Performance
Tested in accordance with BS EN 1264‑2:2021, UnderPlate® achieves up to 70 W/m² at 20°C room temperature with MWT 45°C and 0 tog covering. Performance will vary depending on covering type, pipe centres and building heat‑loss characteristics.
Benefits of the UnderPlate® System
Fits within zero build-up
Fits within the existing floor void for no additional build-up
Aluminium diffuser plate
Enhances heat transfer across the floor surface
Lightweight
Minimal additional load on the structure
Installation from below
Installed from beneath the floor deck
Technical Data
| Specification | Value |
|---|---|
| System Type | Suspended Floor |
| Subfloor | Timber |
| Output (W/m²) | 70 W/m² (based on 20°C room temperature at 45°C mean water temperature and 0 tog) |
| Pipe Size (mm) | 16mm |
| Pipe Centres (mm) | 150, 200 |
| Panel Size (mm) | 1000mm x 200mm x 0.5mm - 0.2m² |
| Floor build up (excluding floor finishes) | 0mm (if within existing joist gap) |
| Maximum loop coverage: | Up to 24m² per loop |
| Heatpump ready | Yes |
| Weight (kg/m²) | 3 kg/m² (Includes plate and pipe) |
UnderPlate® FAQs
UnderPlate® is ideal for retrofit projects where the existing floor finish must remain in place, allowing the installer to fit UFH entirely from below without disturbing the room above.
Why Choose Ambiente?
5-Year System Warranty
A unified 5-year warranty covering all critical UFH components when installed with Ambiente products, giving you and your customers complete peace of mind.
Manufacturing You Can Trust
Designed and manufactured in-house with installer experience at the core, our systems are built for long-lasting performance and reliability you can depend on.
Bespoke Heating Design
Full CAD design service including pipe layouts, heat outputs and flow rates, tailored to your project so the system delivers optimal comfort every time.
Product Technical Support
Access expert technical support throughout specification, installation and aftercare - so you always have the answers when you need them.
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