Humidity
Hardwood floors will contract on their width (and gap) with low winter humidity, and expand in summer.
To avoid this maintain winter relative humidity to about 40% all the time. Since furnace mounted humidifiers often break down, obtain a Humidity Monitor (shown) and keep an eye on it. If humidities drop in cold weather, take action to repair existing humidifiers or obtain portable humidifier(s).
In summer, use of air conditioning is kind to the floor, so it will not appreciably expand. If AC is not available, then ventilate well. Once again keep an eye on the Humidity Monitor. |