Wood flooring responds to variations in humidity by expanding and contracting. In the summer when it is hot and humid, wood floors expand. During the dry cold winter months, wood floors contract. When your wood floors contract in the winter, gaps can appear between the wood planks. This is normal and a homeowner should be prepared for it.
To help prevent your wood floors from gapping in the winter, try to control and monitor the humidity levels by installing a humidifier in the furnace or by bringing a moveable humidifier into the room with the hardwood floors. The optimal humidity levels for your hardwood floors are between 40-60%. If you can keep your humidity levels above 40% no gaps should appear in your hardwood floors.
