A kettle will not supply enough moisture keep up with what an open fire will draw out of the air. Dry winter air is always tough on a wood floor. Try to keep the moisture levels between 35 - 55% year round for the best results.

It is just about impossible outside of a lab setting to maintain relative humidity stable enough to prevent wood movement.

Wider planks are GOING to move more than narrow planks.

See Chapter 3 of the Wood Handbook for more (often painfully detailed) information.

Here is a link that might be useful: Wood Handbook, Chapter 3

In the northern states, Thanksgiving is the start of the crack, gap, split and checking season for wood floors, as the heater dries them out. Stress from low moisture content in the wood, causes damage to the wood fibers, in the form of splitting.

Thanks for this!
Will check out the link.
It's a tough one I guess- wether to baby a soft wood floor which is going to develop a lot of wear naturally.

Your best bet is if you can keep the temperature and humidity at a constant level. This may be difficult at times, such as the winter when you are running the heat. Even still as the wood ages it will certainly swell and contract. That is one benefit of using Reclaimed Wood since it has usually done whatever it's gonna do by the time it is installed.

Here is a link that might be useful: Reclaimed Wood

"That is one benefit of using Reclaimed Wood since it has usually done whatever it's gonna do by the time it is installed."

All wood continues to swell and shrink as the moisture content varies throughout the year.

NO wood is exempt.

Been following this thread with some interest:-)

Brickeyee is right on they do still expand and contract some no matter how old or how long they have been in the house. Our floors have been hanging around since 1825-30 and they open up a 'bit' every winter. Wood type is read oak and clear chestnut, no AC by choice. Its wood it does what it does.