Gaps in glued down floor in high humidity climate

Q: I am buying a house that has old hardwood floors that look great. There is an addition that is newer and the hardwood is installed on a concrete slab. There are some gaps between the boards (the short sides), some as big as about 1/2 inch. The boards are not nailed down due to the concrete. The seller had a guy come out and look at it and he wouldn’t put putty in because he said it would look awful.

Any suggestions? We thought of taking off the shoe molding and trying to slide the boards in the right direction. Would that work? We’re deep in the south with major humidity all the time.

A: Installed on a concrete slab, it has to be glue down. Trying to move the floor out of the position it is in could break the glue bond, and where will that leave you?

I think you need to try to control the environment in the home as best you can. Keep the RH 45-55%.