Choosing the right electric underfloor heating system involves more than selecting the right mat size or thermostat. One of the most important, yet least visible, parts of the system is the heating cable inside the mat. Because the cable becomes a permanent part of the floor build-up, its durability and temperature stability directly affect how well the system performs over time.
However, the insulation material around that cable can vary significantly between products. This insulation is what protects the heating element from heat, movement, compression, and moisture throughout its lifespan. Understanding how this insulation works — and what separates different cable types — can make choosing the right system far easier.
Short Answer: Electric underfloor heating cables use several insulation materials — commonly PVC, PTFE (Teflon) and other engineered polymers such as ETFE or XLPE. Each has different temperature and durability characteristics. The sections below focus on PTFE vs PVC because they illustrate the key differences between entry-level and premium insulation types.
Why the Heating Cable Matters in Underfloor Heating Systems
Electric underfloor heating cables are designed to convert electrical energy into heat, warming the floor surface above them. Because they are embedded beneath tile, stone, wood, or screed, the cables need to:
Perform consistently over many years of thermal cycling
Resist degradation from long-term heat exposure
Withstand compression from the floor layers above
Remain electrically insulated and safe
Once installed, the cable cannot be accessed without removing flooring — which is why longevity and material stability are essential.
While wattage (e.g., 150W/m² or 200W/m²) affects heating performance, it’s the cable insulation that affects how long the system lasts.
How Heating Cable Insulation Works
A standard heating cable is built in several layers, each performing a specific function in protecting the heating element and ensuring even heat transfer.
Conductor Core
At the centre is usually a nichrome (Nickel-Chromium) heating wire, chosen for its stable resistance at elevated temperatures.
Insulation Layer
This is where major differences exist between cable types.
The insulation must:
Resist continuous heat cycles
Resist cracking or embrittlement over time
Two insulation materials often compared in underfloor heating cables are:
PVC (Polyvinyl Chloride)
PTFE (Polytetrafluoroethylene) — sometimes known by the trade name Teflon™ *
PVC vs PTFE Insulation: What the Material Data Shows
| Property | PVC Cable Insulation | PTFE Cable Insulation |
|---|---|---|
| Typical Continuous Temperature Rating | ~60°C – 105°C (depends on formulation) | ~200°C – 260°C – (very high thermal range) |
| Melting Point | ~100°C – 210°C | ~327°C – (extremely high |
| Heat Degradation Over Time | Can harden, crack or soften under prolonged heat exposure | Extremely stable at elevated temperatures |
| Chemical Resistance | Good, but can degrade in alkaline compounds | Chemically inert — one of the most stable known polymers |
| Thickness Needed | Cables tend to be thicker layer to achieve insulation strength | Can achieve the same insulation at lower thickness |
Sources:
MatWeb Material Property Data
Polymer Data Handbook (Oxford University Press)
ASTM D3159 Thermal Insulation Material Data
ISO 2409 Material Stability Under Thermal Cycling
For readers interested in international safety standards, see the official IEC 60800:2021 heating cable standard globally recognised specification for electric underfloor heating systems.
Wider Comparison of Electric Underfloor Heating Cable Materials
| Material | Max Operating Temp | Flexibility | Durability | Typical Use | Cost | Notes |
|---|---|---|---|---|---|---|
| PVC (Polyvinyl Chloride) | ~70–105 °C | Very flexible | Moderate | Entry-level UFH cables | £ | Easy to install, but degrades faster at high heat |
| XLPE (Cross-Linked Polyethylene) | ~110 °C | Medium | High | Mid-range cables and mats | ££ | More heat-resistant and tougher than PVC |
| PTFE (Polytetrafluoroethylene / Teflon) | ~200 °C | Medium | Very high | Premium cables | £££ | Excellent chemical and heat resistance |
| ETFE (Ethylene Tetrafluoroethylene) | ~150 °C | Medium-stiff | Extremely high | Industrial or high-spec systems | £££ | Slightly stiffer than PTFE |
Performance notes based on IEC specifications and manufacturer technical data (Chemours, DuPont, Prysmian, MatWeb)
Sources:
Chemours Teflon™ PTFE Properties Data
DuPont Tefzel™ ETFE 200 Product Information Sheet
IEC 60800:2021 – Heating Cables for Comfort Heating
IEC 60502-1 – Power Cables with Extruded Insulation (XLPE)
IEC 60227 – Polyvinyl Chloride Insulated Cables (PVC)
MatWeb Polymer Property Database
Why Temperature Resistance Matters in Floor Heating
Electric underfloor heating cables operate within a controlled but warm environment, and the floor above can sometimes act as a thermal barrier. Because flooring materials vary in conductivity (e.g., tile vs. engineered wood), the cable may operate at slightly elevated temperatures during normal use.
When insulation materials approach their thermal stability limits, they may:
Soften
Harden
Lose flexibility
Crack under stress
Degrade electrically
This is why higher temperature tolerance equals longer cable life.
PTFE does not soften or break down in these operating conditions — it remains stable far above the temperatures seen in normal electric underfloor heating.
Dual-Layer PTFE (Teflon™) Cable Construction
Some modern heating cables use two layers of PTFE insulation, rather than a single layer or PVC. The purpose of a dual coating is to provide:
Additional mechanical durability
Higher resistance to pressure during floor installation
Greater safety margin during thermal expansion and contraction cycles
This design aims to support the cable remaining stable and flexible over decades, not just during initial installation.
PTFE, commonly known as Teflon, is part of the fluoropolymer family — sometimes referred to as fluoroethylene cables. These high-temperature insulations are valued for their exceptional heat and chemical resistance, making them a popular choice for premium electric underfloor heating systems where long-term reliability is essential.
UFH Direct offers Lifetime Warranty on their premium dual Teflon™ coated cables and mats*
How to Identify High-Quality Heating Cable Insulation
When comparing electric underfloor heating cables, look for clear information on how the insulation is constructed and tested. A reliable product will usually include:
Declared insulation material (e.g. PVC, XLPE, ETFE) with published temperature and safety ratings
High-purity heating conductors, such as nickel-chromium (NiCr) or tinned copper, for stable resistance and even heat output
Braided or foil earth screen to improve grounding and reduce electromagnetic interference
Dual-layer or reinforced insulation, offering added mechanical strength and resistance to damage during installation
Consistent outer diameter, showing precise manufacturing tolerances and uniform insulation thickness
These features help ensure the cable will remain stable and safe under the temperature cycles typical of electric underfloor heating systems.
Final Thoughts: Matching Cable Type to Installation Needs
So, What Is the Best Cable for Electric Underfloor Heating Mats?
There’s no single “best” brand, but the insulation material plays a major role in long-term cable performance. PTFE generally offers the highest level of thermal and chemical stability, making it ideal for demanding or long-lifespan installations. ETFE performs similarly in many respects, providing excellent durability with added mechanical strength. XLPE offers a dependable mid-range balance, while PVC remains popular for entry-level mats where cost and flexibility are the priority. The most suitable choice depends on the project’s temperature range, budget, and expected lifespan.
Need Help Choosing the Right Cable for Your Project?
If you would like help checking a specification, understanding insulation types, or selecting the right system for your floor finish, our technical team can help.
There’s no obligation — just ask.
Contact us for free guidance or call 01752 717911
For readers who’d like to explore real-world examples of heating cables
see our Electric Underfloor Heating Mats range.
Related Reading
To understand how electric systems compare with warm-water (hydronic) systems:
Learn more about Electric underfloor heating vs water underfloor heating
References & Source Material
Polymer Material Data & Thermal Properties
MatWeb – Material Property Database
PTFE (Polytetrafluoroethylene) material propertiesPolymer Data Handbook (Oxford University Press)
Edited by J.E. Mark
ISBN: 978-0195107890
Thermal Stability / Heat Cycling Behavior
ASTM D3159 – Standard Test Method for Thermal Insulation Heat Stability
ISO 21465 – Paints, varnishes and plastics: Thermal cycling & adhesion testing
British Plastics Federation – Polymer Thermal Properties Guide
Electrical Insulation & Wire Standards
IEC 60800:2021
Heating Cables for Floor Heating – Safety & Performance RequirementsBS 7671:2018 (IET Wiring Regulations)
Requirements for fixed electrical installations (UK)UL 94 – Flammability & Thermal Response of Polymer Insulation
Chemical Resistance & Polymer Stability
Journal of Applied Polymer Science
“Thermal oxidative degradation of PVC vs fluoropolymer materials”
DOI: 10.1002/app.48213
General Engineering References
Engineering Toolbox – Polymer Melting and Glass Transition Temps
ScienceDirect – PTFE Thermal Aging and Molecular Stability
*Our Lifetime Warranty protects the original UFH Direct heating mat for as long as the first floor covering remains in place. The warranty applies only when installed to our instructions and becomes void if the mat is relocated, the floor is replaced or altered, or the system is otherwise modified or damaged after installation. Proof of purchase is required.
*Teflon™ is a registered trademark of The Chemours Company FC, LLC. Any reference to Teflon™ in our product descriptions is used solely to describe the coating material applied to the cables. UFH Direct is not affiliated with, sponsored by, or endorsed by Chemours
