Underfloor heating can work successfully with most floor coverings, however some are better at transferring heat than others.
What are the best floor coverings for underfloor heating?
Stone and ceramic surfaces
The best floor coverings for use with underfloor heating are hard surfaces such as stone and ceramic tile as they have the least resistance and transfer heat effectively. As the most thermally conductive of all floor coverings, energy from the heating pipe array can transfer quickly to the surface of the stone/tile. Increasing the thickness will have little effect on power output, but will slightly increase heat-up times.
It is always advisable to use a de-coupling membrane and flexible adhesive with solid floor finishes to reduce the potential for hairline expansion cracks; large areas will also benefit from expansion joints, especially through doorways. The flooring supplier will be able to offer advice on specific coverings.
- Ceramic tiles
Due to their high thermal conductivity and slim profile, ceramic tiles are one of the best floor finishes for use with underfloor heating.
- Polished screed
Very conductive and perfect for use with underfloor heating.
Stone is the most thermally conductive of all floor coverings allowing energy from the UFH to transfer quickly to the room.
An extremely conductive natural finish, ideal for use with underfloor heating.
A thicker stone finish that exhibits very good thermal conductivity
An excellent heat conductor available in varying thicknesses
Timber flooring and underfloor heating
Engineered timber is the best option for use with underfloor heating as its structural stability allows it to perform well with fluctuating temperatures. Solid hardwoods and soft woods also transfer heat well but care should be taken when specifying board width and thickness.
- Engineered timber
The best timber floor finish for use with UFH, offering very good heat transfer
- Solid hardwood
Good heat transfer and ideal when specified in narrow board widths
Suitable only in narrow board widths to reduce movement
- Traditional parquet
Offers good heat transfer when securely glued to the sub-floor
Usually similar in construction to engineered timber, making it very suitable for UFH
Laminates, vinyl and rubber
Laminates and vinyls also perform extremely well with underfloor heating. It is advisable to check the manufacturer’s recommended maximum floor surface temperature to ensure the product is suitable for use with UFH. Most manufacturers state 27˚C, which equates to approximately 75W/m2 of heat output, which is more than adequate in most situations. These products heat up and cool down quickly in comparison to stone and timber.
Very good heat transfer, often subject to a recommended maximum surface temperature
A practical, high-quality finish that transfers heat very well
- Linoleum & Marmoleum
These are thin natural products that are very well suited to use with underfloor heating
- Laminate tiles
Thin and very thermally conductive making them perfect for use with UFH
A relatively thermally conductive material that can easily be used with underfloor heating
Which floor coverings are least likely to perform?
Carpet and underlay with a combined Tog value of up to 2.5 can be used effectively with underfloor heating. Thicker carpets act as an insulator and stop sufficient heat reaching the room. Nu-Heat’s comprehensive system design will factor in the extra heat output that will be needed if carpet is specified.
A maximum Tog value of 2.5 is recommended for carpet and underlay when used with underfloor heating
A maximum thickness of 10mm is advised as cork is an efficient insulator
A natural product similar to carpet that is subject to a maximum recommended Tog value of 2.5
Some flooring manufacturers stipulate a maximum floor temperature for their product; please advise Nu-Heat if this is the case so it can be factored into the system design. Nu-Heat adheres to BS1264, which states that underfloor heating should not operate at more than 29˚C.
As part of our complete design service, Nu-Heat is happy to advise on suitability. If you are planning on using a floor covering not listed, please contact us for advice.