When parquet becomes cracked in winter, the humidity in the room is not right. It is usually not the quality of the parquet! The natural product wood can bind and release water (hygroscopicity). The wood moisture content with which parquet is delivered and laid is approximately nine percent with a deviation of 2 percent each way up and down (different limits apply depending on the type of parquet). In order for this condition to remain unchanged, a humidity of 55 to 60 percent is required. These factors change due to the weather and heating behaviour. This causes small cracks to appear, but these recede again when the room climate is correct. One should avoid strong temperature fluctuations when heating. A good preventive measure is a humidifier, preferably a so-called evaporator, which keeps the air humidity constant at a level of 55 to 60 percent.