A common issue with hardwood flooring is gaps and separations between planks. Hardwood flooring is a natural product that is affected by variations in temperature and humidity. During warm, humid summers hardwood absorbs moisture and expands. Conversely, dry winter weather causes hardwood to lose moisture and contract.
Gaps and separations often concern homeowners, but this seasonal movement is completely normal. However, there are some things you can do to prevent gaps and separations. The simplest approach is to address any existing moisture issues in your home.
There is a direct relationship between temperature, moisture, and relative humidity. Excessive ventilation in the winter tends to dry out the air inside your home. When you bring cold winter air inside, the relative humidity drops significantly. More ventilation results in dry air, which pulls moisture from your hardwood floors.
Ventilation is measured in air changes per hour (ACH). Modern building codes recommend home ventilation rates near ⅓ ACH. An average home typically has a ventilation rate between 1 and 2 ACH. Older homes can have ventilation rates near 10 ACH, with windows often being major leakage sites. Home weatherization can help solve ventilation problems that may lead to dry hardwood floors.
If you want to raise the relative humidity in your home, you may need to add moisture to the air. Since the ventilation rate is related to moisture, the best way to prevent gaps and separations is to reduce ventilation rates, then add moisture. Normal household activities can add moisture to the air. When that is not enough, you may need to use a humidifier. A typical humidifier can add up to 6 pints of moisture to the air per hour.
The Bottom Line
Winter weather tends to dry out hardwood flooring, which can lead to gaps and separations. To minimize the impact of cold temperatures, take steps to reduce ventilation and, if necessary, add moisture to the air with a humidifier. Indoor temperatures should be kept in the range of 65 to 75 degrees Fahrenheit with a 50 to 70 percent humidity level.
Source: Horizon Forest Products Blog Jan 2016