Separations during cooler months

Q: Two years ago we had our 30+ year old oak living room floor refinished. The results were excellent! We had the same guys install a new site finished oak floor in another room this year. The new wood was allowed to sit in the room for about 3 weeks this fall to adjust to the temperature and humidity characteristics of the house.

A product that they referred to as liquid oak was used during finishing. I understand completely ( from the old floor refinishing ) that during the cooler months, separations will appear between planks and subsequently close with warmer conditions. My concern is that some of the separations in the new floor have a very jagged appearance. Both the finisher and I agree that this resulted from the liquid oak separating alternately on each side of the boards as the wood contracted. In a small ” test ” area, he used a putty type product intended to fill such openings. Would you advise applying this ” putty ” along all of the openings? Do you have any suggestions? Am I better off to see this through for a year of expansion and contraction?

A: I would see it through for a season. If the floor expands in summer, what is going to happen to the putty? I would suggest trying to maintain in house humidity to between 36-42% in winter. You may need to buy a humidifier and hygrometer to keep check on the environment. I have not heard of this particular finish. Some coating will stretch a bit.