Regardless of what flooring specifies of wood you have it is important to remember that wood is an organic product and is affected by the water present in the wood at any given time. The fibers within the food are constantly changing because of the solidity, flexibility and tension of the fibers.
The conditions in your home are constantly changing and can have an affect on the wood in your home. The outdoor temperature, the HVAC system in your home and the tightness of your home can all affect your wood. Changes are commonly seen in hardwood flooring during the winter because of the heating system. The wood loses moisture during the winter which causes it to contract and create gaps.
Acclimating the hardwood is a big part of preventing gapping. Allowing the hardwood to match the ambient humidity and temperatures of your home before installation is vital. If there is a difference between the moisture content in the sub-floor and the flooring is is more likely to cause shrinking and gapping or even buckling in some situations. The duration of the acclimation process varies based on the season, air tightness of your home and the local weather.
In home humidity factors are also a big element in gapping. The humidity of your home is most likely to cause expansion and contraction in your hardwood. Keeping the temperature and humidity constant can best decrease the risk of gapping. A humidifier is a great way to keep the moisture level in your home higher during the drier months.
Gapping is not the end of the world but by acclimation and humidity control you can keep your gapping to a minimum.