What types of wood flooring can be installed with underfloor heating?

To establish whether your wood flooring is compatible with underfloor heating or not, you first need to find out about heat conduction to the floor’s surface. Depending on the structure and sizes of the flooring strips themselves, wood flooring may or may not be compatible with underfloor heating systems. Where compatibility has been established, it is of course essential to pay careful attention to the advice given regarding installation of the floor. There are some fairly stringent conditions to satisfy before installing the chosen wood flooring. This is due to the fact that it needs to both conduct the heat generated by the heating system and tolerate the effects of temperature changes without distorting.

The underfloor heating must be of the “low temperature” kind (up to 28°C). Heat distribution must be uniform, with no temperature variations. Additionally, only wood flooring with a thermal resistance lower than 0.15 m2 K/W must be used.Wood flooring compatible with underfloor heating is normally labelled as such.

The criteria for compatibility generally vary from one wood flooring type to the next:

- For solid wood flooring: the flooring’s thickness must be no greater than 15 mm. Strip width can be no more than 120 mm whether the wood species is European or Exotic. Larger dimensions are to be avoided due to a risk of excessive expansion.

The wood flooring must be fully glued-down (across the whole bottom surface of the strips) directly onto screed or onto a suitable insulating material, itself fully glued down onto the screed: this is known as double glue-down installation. The glue used must also be suitable for use with underfloor heating (allowing heat conduction).

- For engineered wood flooring: only those types with a multi-layer core should be used. Wider strip sizes are perfectly compatible with underfloor heating. This is one of the biggest advantages with engineered wooden flooring. Though it offers a greater range of choice than solid wood, it is imperative that this type of wood flooring is installed using the same methods and adopting the same precautions, namely: full glue-down.

- For laminate flooring: due to its construction, this type of wood flooring is very often compatible with underfloor heating. It is laid using the floating installation method and a suitable insulating underlay. There are no dimensional restrictions. Always check the manufacturer’s indications for compatibility however: some types of budget-range laminate flooring are not suitable for use with underfloor heating.

To summarize, this is what needs to be taken into account:

Solid wood flooring:
Strip thickness: < / = 15 mm
Strip width: - Oak: < / = 120 mm
- Exotic woods: < / = 120 mm
Installation method: Full glue-down onto screed, or onto a suitable insulating material using the double glue-down method

Engineered wood flooring with a multi-layer core:
Strip thickness: < / = 20 mm
Strip width: No restrictions
Installation method: Full glue-down onto screed, or onto a suitable insulating material using the double glue-down method

Laminate floor:
Strip thickness: No restrictions
Strip width: No restrictions
Installation method: Floating installation onto a suitable sub floor