The Effects of Heating and Humidity

Wood is a natural material which reacts to its environment. Even though the three-layer structure of Upofloor’s RealWood hardwood flooring minimises expansion and contraction, it is important to maintain an ideal, constant temperature and the right humidity in the room. The same conditions are often also ideal for people.

Indoor air humidity
The relative humidity of the air indoors depends on the atmosphere outside and the humidity produced by every day life.The relative humidity should remain within 40­ - 60% throughout the year. During long dry periods, the air indoors may become too dry, and additional humidity is needed. During rainy and warm conditions, the air humidity indoors is prone to rise, which can be balanced with additional heating. For a hardwood flooring however, excessive dryness is more harmful than too much humidity.

If there is very little humidity produced during normal conditions or if the premises are left empty in dry weather for over a week, it is advisable to lower the temperature to around 15 °C and set the air-conditioning to minimum. In this way, the humidity of the air is slightly increased and the risk of damaging the hardwood floor is reduced.

During long empty periods, it is advisable to fill the kitchen sink and the bathroom sink with water and place vessels filled with water in the rooms. The humidity evaporating from these has a positive effect on the atmosphere indoors.

In damp weather, there may be too much humidity in the air. The humidity of the wood can be decreased by using floor heating, even though the temperature is not raised.

Air humidity in the room
1. When the air outside, with a temperature of ­10 °C and a relative humidity RH of 90% is heated to 20 °C, the relative humidity of the air drops to 10%. In this case, increased humidity is needed to reach the recommended air humidity level.

2. When the air humidity indoors is 40% at a temperature of 20 °C and the surface temperature of the hardwood floor is 28 °C, which is the recommended maximum temperature for floor heating, the humidity near the hardwood floor is approximately only 25%.

3. When the humidity produced by the atmosphere outside on the air indoors is, for example, 25%, normal living (for example, cooking, doing the laundry, indoor plants, etc.) adds to the humidity so that the air humidity rises to approximately 35%, which is very close to the recommended humidity level.

An air hygrometer nearly always indicates readings higher than the real values. Thus, if the hygrometer indicates, for example, 35%, the real humidity may even be under 20%, in which case additional humidity would be needed.