CONDITIONS FOR INSTALLATION OF WOOD FLOORING OVER UNDERFLOOR HEATING SYSTEM AND DRYING OUT A RADIANT HEATED CONCRETE SLAB


Wood flooring is not suitable for installation over electrical underfloor heating systems.

Concrete slab should be laid in accordance with specifications and standards of the manufacturer. The slab must be flat and level, compact, dry, free of cracks and clean. Radiant heat tubing should be placed properly at least 35mm below the surface to ensure an equal distribution of heat. Unless the tubing is laid deep enough, it can result in extensive joint opening in the installed wood flooring.

The highest allowed moisture contents prior to wood floor installation are 1,8 % with radiant heated cement slab and 0,3 % with radiant heated anhydrite slab.
After the 21-day drying period recommended for concrete slab (at least 7 days for anhydrite slab), the heating system should be turned on according to the following procedure

 

Wood floor installation1. day …………….. 25 °C
2. day …………….. 30 °C
3. day …………….. 35 °C
4. day …………….. 40 °C
5. day …………….. 45 °C
6. day …………….. 50 °C
7. day …………….. 55 °C
8. -20. day ………. 55 °C
21. day …………… 50 °C
22. day …………… 45 °C
23. day …………… 40 °C
24. day …………… 35 °C
25. day …………… 30 °C
26. day …………… 25 °C
27. day ……………Slab moisture content measurement according to CM method.

 

Wood floor installation should not begin until slab moisture content is in accordance with the standards of wood floor installation requirements. If this is not the case, drying should continue at 40°C, until we have reached the prescribed slab moisture content. Adequate ventilation should be maintained during the drying period (no draught).

Prior to wood floor installation, the temperature should be gradually decreased until 2-3 days before installation is to be shut down. Recommended room temperature, that should be maintained at this stage, is 18°C. 3 days after wood floor installation, the underfloor heating system should again be switched on and gradually increased to operating temperature.
When wood floor is installed, the surface temperature of radiant heated concrete slab should not exceed 25°C. Relative air humidity should be kept between 50 and 60 %.
 
 Under floor heating systems