Carbon film heaters are best known for use under carpet, but carbon film heaters under parquet and laminate are also very common. Ceramic tiles are a different matter. In this article we explain suitability for each floor type, the installation layers and the temperature limits.
Suitability by Floor Type
| Floor | Suitable for Carbon Film? | Note |
|---|---|---|
| Laminate | Yes | Choose products labelled as suitable for underfloor heating |
| Engineered parquet | Yes | Follow the manufacturer’s surface temperature limit |
| Solid wood parquet | Limited | Thick, wide solid boards risk movement; manufacturer approval required |
| Carpet / fitted carpet | Yes | Avoid rubber-backed and very thick carpets |
| Ceramic tile / marble | Generally not recommended | A heating mat or heating cable is preferred |
| Vinyl / LVT | Conditional | Only if the manufacturer permits underfloor heating, at low temperature |
Installation Layers Under Laminate and Parquet
- Flat, clean subfloor: The existing screed or old covering must be level.
- Thermal insulation underlay: Prevents heat escaping downwards. Details: should you lay felt underneath?
- Carbon film: Laid with the copper busbars facing down or as specified by the manufacturer; strips must not overlap.
- Moisture barrier (PE foil): Laid over the film to protect it and the floor covering from moisture.
- Laminate/parquet: Installed as a floating floor; no nails or screws that could pierce the film.
Temperature Limit
For laminate and parquet, the floor surface temperature is usually limited to 27 °C, so a thermostat with a floor sensor is essential. See our surface temperature guide.
Why Is Carbon Film Not Recommended Under Tiles?
- Tile adhesive is a wet material, and carbon film is not designed for direct contact with moisture.
- Adhesive does not bond to the PET surface, so tiles may come loose over time.
- If a fault occurs, the tiles must be removed to reach it.
For tiles, marble and bathrooms, a heating mat or heating cable is the right solution. For a comparison, read carbon film vs electric underfloor heating and our cable underfloor heating guide.
Installing Over an Existing Tiled Floor
If you do not want to remove an existing tiled floor, you can install thermal insulation underlay, carbon film, a moisture barrier and laminate or carpet on top of the tiles – no demolition required.
Frequently Asked Questions
Will carbon film crack my parquet?
With suitable parquet and a limited surface temperature, cracking is not expected. For thick solid parquet, obtain the manufacturer’s approval.
What film power should be used under laminate?
Typically 150–220 W/m². See our sizing article for the calculation.
Conclusion
Carbon film heaters can be used safely under laminate, engineered parquet and carpet, while cable systems should be chosen for tiles and wet rooms. Contact us for a solution that suits your floor.
