Installation on floor heating
Board parquet can also be installed on subfloors with underfloor heating, following the technology. The thermal resistance of hardwood floors is favorable, neither too high nor too low. A wooden floor always feels warm underfoot, even if the underfloor heating is not working. Industrial hardwood floors expand and contract significantly less than solid wood floors. Wood species such as beech and maple react very quickly to unfavorable climatic conditions, as a result of which cracks may appear between the boards. In the case of underfloor heating, it is recommended to use wood species with little movement, such as oak. The surface finish must also be taken into account. Surface finishes with open pores such as oils and waxes react to changes in room climate much faster than environmentally friendly varnished surfaces.
- Important requirements for the substrate:
It is recommended to use low temperature floor heating systems. The maximum temperature of hot water flowing in underfloor heating can be 55º C.
The minimum mixture layer above the heating pipe is 40 mm.
In the case of A3 type floor heating, the heating pipes are installed in the center of the subfloor. This means that the moisture in the bottom zone of the subfloor does not dry out in the first heating phase. Therefore, a two-step heating/de-heating procedure with an intermediate cooling phase is necessary.
Before putting the heating system into operation, the cement floor must dry for at least 21 days and the anhydrite floor for at least 7 days.
The heating protocol for heated subfloors must be handed over to the customer and must be approved by the customer. One copy must always be with the order documents. If there is no such heating protocol or it seems unreliable after careful review, the customer must be informed in writing.
When testing, it is mandatory to measure the humidity of the subfloor at the measurement points specified by its builder. If such measurement points are not marked, this must also be reported in writing. The measuring points must be marked afterwards or at least draw attention to the crucial importance of the heating protocol in this case in order to exempt yourself from warranty liability in case of possible defects.
The maximum residual moisture for cement floors is up to 1.8% (CM), for anhydrite floors a maximum of 0.3% (CM).
It should be noted that there is a reasonable relationship between the thermal resistance of the layers above the heating element (subfloor or top layer) and the thermal resistance of the subfloor (thermal insulation) below it. The downward spread of heat must not exceed 20 W/m2 or 25% of the heat output. Therefore, the thickness of the wooden floor covering should generally not exceed 22 mm (for hardwood).
- After installation, the homeowner must:
- Avoid sudden fluctuations in the room climate.
- Keep the room temperature constantly at 20-22º and the relative humidity at about 55%. We recommend using a humidifier during the heating period. Avoid unnecessary sources of moisture during the summer months.
- The temperature of the hardwood floor surface must not exceed 26º C.
- Thermal resistance values in case of gluing:
- 14 mm 3-layer parquet 0.080 m2/K/W 1
- 10 mm 2-layer parquet 0.048 m2/K/W
The limit value of 0.17 m2/K/W must not be exceeded.
Three-layer hardwood floors are only partially suitable for floating installation, so we recommend gluing.
In general, gluing is recommended for underfloor heating.
Boards from species such as beech, Canadian maple, jatoba and bamboo are not suitable for underfloor heating due to the specific properties of wood.