Wooden floors for underfloor heating

Wood is an excellent insulator, which is why before choosing wooden flooring for underfloor heating, it is worth gaining basic knowledge about the thermal conductivity and thermal resistance of the products offered to you.

Before purchasing flooring, it is worth asking the seller for comparative test results for different types of wooden floors.

Unfortunately, there are many companies on the market that take advantage of the end customer’s lack of knowledge, claiming that every wooden floor is suitable for underfloor heating, which is simply not true.

Which floor for underfloor heating?

In the text below, we present general information and useful knowledge that will help each of you choose the right and beautiful wooden floor for underfloor heating, which will also serve as a durable and functional finish for an apartment or house interior.

Are wooden floors for underfloor heating a good idea?

Before making any investment decisions, it is worth considering the choice of the right flooring for underfloor heating. A common question is whether wooden floors can be used for this purpose, as they are usually associated with elegance and nature rather than modern technologies. The answer is clear — yes, but it is necessary to choose the right wood species so that the flooring performs properly and heats the room efficiently.

That is why it is best to choose wooden parquet flooring with good hygroscopic properties and a low longitudinal and transverse shrinkage coefficient, so that gaps do not appear between the boards during the heating season.

It is best to use classic European oak, ash, or exotic species such as merbau, doussie, or jatoba. Long-term maintenance of a dry indoor climate may lead to micro-cracks in the floor, and the boards may deform in multiple directions. Relative air humidity should not be allowed to fall below 30%, because in such conditions the wood dries out rapidly, which may cause permanent surface damage. The floor surface temperature must also be controlled and should never exceed 27 degrees Celsius. Canadian maple and beech should be avoided, as these species have too high a shrinkage coefficient.

Wooden boards – what type of heating?

An important aspect is the choice of underfloor heating type. There are two options available: electric or water-based heating. The first comes in the form of special heating mats installed in the cement adhesive layer or in the screed layer beneath the floor finish. It is a simple and quick way to install underfloor heating under flooring surfaces. An important element of this system is the use of a suitable thermostat, thanks to which the heating system can be controlled, allowing optimization of efficiency and energy consumption, which in turn results in considerable savings in heating costs.

A more popular solution is water-based underfloor heating, which distributes heat evenly and thus provides enhanced comfort in everyday life.

Wood species with a high shrinkage and swelling coefficient should be avoided, as their use in this system is not recommended. We advise against beech and maple boards, as well as wooden floors made from birch or hornbeam, among others.

To avoid making the wrong choice, it is worth acquiring basic knowledge in order to be a well-informed partner in discussions with the seller and to choose the best floors for underfloor heating, ones that work perfectly with both systems without exposing yourself to dangerous situations or unnecessary costs in the future.

Our wooden boards for underfloor heating can be used with both water-based and electric systems. However, as it is worth repeating, the floor surface temperature must be controlled and must not exceed 27°C in any part of the parquet, including under furniture or rugs. High temperatures or an excessively dry indoor climate may cause gaps to appear. Underfloor heating should be distributed evenly beneath the entire parquet floor. If you intend to install it only in part of a room, the heated and unheated sections should be separated by an expansion gap.

Engineered flooring or solid wood board?

What works best with underfloor heating? Wooden floors installed over underfloor heating systems are much more exposed to drying out than those installed on traditional screeds without heating. It is recommended to use engineered flooring, which is incomparably more stable than solid wood boards. Engineered flooring ensures even stress distribution.

By choosing engineered flooring, the user gains much greater flexibility in terms of dimensions — they can be much larger than solid boards. With heating systems, very large wood elements can be used with relatively low risk, for example boards up to 3 meters long and very wide elements up to 30 cm wide, without fear that the floor will warp or deform as a result of the heating system.

It is recommended that the thickness of multilayer flooring for underfloor heating should not exceed 10 mm, and its thermal resistance should not exceed 0.05 m2 K/W. Using flooring thicker than 10 mm results in high thermal resistance, which makes the heating inefficient and significantly increases energy costs needed to properly heat the rooms.

What about solid boards? It should be remembered that solid boards have worse thermal transfer parameters and a higher coefficient of longitudinal and transverse shrinkage and swelling, which may in some cases lead to floor damage, multidirectional deformation, and a reduction in the aesthetic quality of the surface under high temperatures.