The acceptable moisture content for hardwood floors in service varies depending on the species of wood and the prevailing environmental conditions.
Generally, it's recommended that the moisture content of a hardwood floor be between 6% and 9%. Acceptable range, however, may vary slightly depending on the specific wood species and climate.
If the moisture content is too low, the wood can become brittle and prone to cracking. If the moisture content is too high, the wood can swell and buckle.
Moisture content can be measured using a moisture meter. It is important to take readings from multiple locations on the floor to get an accurate average.
If the moisture content of a hardwood floor is outside of the acceptable range, it may be necessary to take steps to adjust the moisture levels. This can be done by using a humidifier or dehumidifier.