The ThermoSphere Foil is an award-winning electric underfloor heating system for wood, laminate, carpet and vinyl floor finishes. At 140W/m² and just 1.5mm thick, it is the go-to solution for floating floors in bedrooms, living rooms, dining rooms and hallways. It is the only foil system in the UK fully compliant with Section 753 of the 18th Edition Wiring Regulations — straight from the box. Unique features: continuous protective earth braid, accessible cable loops, double aluminium foil for even heat distribution. Available as foil-only or as a complete kit with underlay and overlay. Lifetime warranty on registration.
140W/m²
Output
1.5mm
Thickness
Section 753
18th Ed. Compliant
IP68
Protection
29°C
Max Floor Temp
Lifetime
Warranty
Key Features
Only Foil System Fully Compliant with Section 753 — 18th Edition
ThermoSphere Foil is the only foil electric underfloor heating system in the UK fully compliant with Section 753 of BS 7671 (18th Edition Wiring Regulations) straight from the box — no additional accessories required. Essential for regulatory compliance on residential and commercial projects.
Section 753 compliant18th Edition
Continuous Earth Braid — First Fully Earthed Foil in the UK
A continuous protective earth braid runs the entire cable length — a feature unique to ThermoSphere. Most competitor foil systems have no continuous earth protection. ThermoSphere introduced this in 2015, making it the safest foil system available.
The exposed, accessible cable loops at the end of each foil run allow the foil to be cut and turned to start a new row without risk of cutting the cable. The loop also protects the heating element from abrasion after installation.
Accessible loopsEasy installation
140W/m² — 1.5mm Thick — Minimal Floor Build-Up
At just 1.5mm thick, the foil itself adds almost nothing to floor height. With the complete kit (foil + 5mm underlay + 2mm overlay) the total build-up is ~8–9mm. Maximum floor surface temperature: 29°C (thermostat-limited). Maximum timber board thickness: 18mm.
1.5mm foil~9mm total kit29°C max floor temp
Suitable for Wood, Laminate, Engineered Timber, Carpet and Vinyl
Compatible with all common floating floors: solid wood, engineered timber, laminate, LVT, vinyl and carpet. For carpet, total tog (carpet + underlay + HDF overlay) must not exceed 2.5 tog. Not suitable for tile or stone — use Mesh or Membrane for hard floors.
Wood / Laminate / Carpet / VinylMax 2.5 tog for carpet
IP68 — Safe in Wet Rooms and Bathrooms
IP68 rated — completely impervious to moisture, safe in wet rooms, shower areas and bathrooms when installed with appropriate accessories.
IP68Wet room safe
Lifetime Warranty — Stays with the Property
Backed by a lifetime warranty when registered online. Uniquely, the warranty transfers with the property on sale — the new owners remain covered.
Lifetime warrantyProperty warranty
Technical Specifications
Technical Data
Voltage
230V / 50Hz
Output
140 W/m²
Max Thickness (foil only)
1.5mm
Width
500mm (heated width 450mm)
Cold Tail Thickness
4mm (concealed in insulation)
Max Floor Surface Temperature
29°C (limited by thermostat controls)
Max Timber Board Thickness
18mm
Protection Rating
IP68
Wiring Compliance
Section 753 of BS 7671 (18th Edition Wiring Regulations)
Warranty
Lifetime (online registration required)
Country of Origin
United Kingdom
ℹ Installation: All electrical connections must be made by a qualified electrician in accordance with BS 7671. Register your product with ThermoSphere online to activate your lifetime warranty.
Frequently Asked Questions
What floor finishes work with ThermoSphere Foil?
Engineered timber, solid wood, laminate, LVT, vinyl and carpet. For carpet, combined tog of carpet + underlay + HDF overlay must not exceed 2.5 tog. Not suitable for tile or stone — use Mesh or Membrane instead.
Do I need underlay and overlay as well?
Yes — foil must be used with a cushioning underlay (5mm) and overlay (2mm). Buy separately or as the complete kit (foil + underlay + overlay in one box).
What is Section 753 and why does it matter?
Section 753 of BS 7671 sets requirements for heating systems in floor constructions. ThermoSphere Foil is the only foil system fully compliant straight from the box — increasingly required by electricians and building inspectors.
Can I cut the heating cable?
Never cut the cable. Cut only the foil at the loop points to turn corners. The cable loops are specifically designed for this cut-and-return step.
What thermostat should I use?
Any ThermoSphere thermostat with a floor sensor input. The T-MO (Wi-Fi/BLE, energy metering) is ideal for scheduling and monitoring.
Related Products
ThermoSphere Foil Kit (with Underlay and Overlay)
Complete kit — foil + underlay + overlay
ThermoSphere T-MO Thermostat
Smart Wi-Fi/BLE thermostat
ThermoSphere Mesh 150W/m²
For tile and stone floors
BTU & WATT Calculator
Room Dimensions
Room Type
Living Room
Bedroom
Kitchen
Bathroom
Conservatory
Hallway
Glazing Type
Single Glazed
Double Glazed
Triple Glazed
External Walls
0 Wall
1 Wall
2 Walls
3 Walls
4 Walls
Insulation Level
Poor
Average
Good (New Build)
Required Heating
0
Watts
0
BTUs
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