Wow, that's quite a flood. It doesn't happen often, I hope!
I put the dehumidifier in there just to make sure I could draw down the moisture if I wanted to, and to see if it had a noticeable effect on the flooring (after a few days there wasn't much if any difference).
Also, I found this publication from the National Wood Flooring Association that was really very helpful for me to understand this, and also quite consistent with most of what folks here said. Here's the link in case anyone is interested:
http://www.goldenstateflooring.com/documents/waterandwood.pdf
There's a table in the pdf that shows what woods tend to move the most with changes in moisture levels. According to the table, maple is one of the bigger movers. There is also a description of a situational variable common to cottages that probably really applies to me (and maybe others here, as well):
RELATIVE HUMIDITY: When humidity increases, the effect on the wood floor can be damaging. This occurs most frequently in homes in which occupants are there for a short period of time, such as a week- end home or vacation cabin, or in rooms that are closed off (not heated) to save energy.
If air conditioning or heating is not used or is shut off, ventilation is a must even when the home is not occupied. Otherwise, the floor will expand in the high humidity, and cupping and buckling will occur. This “greenhouse effect” will be exaggerated even more when a plank floor has been installed, because wider boards react to moisture with more movement.
In addition to being able to dial in the desired RH, the dehumidifier I bought has a timer on it. During the summer, rather than running the dehumidifier while we were away, I thought I could play around with setting the timer for a couple of hours after we leave to pump out humidity we drew in while opening the house up. Regardless, I think the wood must be pretty well acclimated now (it's been down for about 9 months). If I can get the floor relayed in the next couple of weeks with new expansion gaps, I think it would be in the middle of it's typical zone and should be able to expand and contract in response to typical fluctuations for the region. I also might consider just leaving some windows open during the summer to allow the house to breathe a bit more.
Finally, this was amazing to me:
GROWING BOARDS - How much can temperature and humidity affect the dimensions of a hardwood floor? Take a look at one 5-inch red oak plank board:
1) Within “normal living conditions” (say, an interior temperature of 70 degrees and a relative humidity of 40 percent), the board has a mois- ture content of 7.7 percent and is 5 inches wide.
2) If the relative humidity falls to 20 percent, the moisture content of the board will be 4.5 per- cent, and the same 5-inch board will shrink by .059 inches. Across 10 feet of flooring. that could translate to as much as 1.4 inches of shrinkage.
3) If the humidity rises to 65 percent, the board’s moisture content would be 12 percent and the same 5-inch board would expand by .079 inches. Across 10 feet of flooring, this could translate to 1.9 inches of expansion.
Almost 2 inches across 10 feet! No wonder my floors are buckling....
Thanks again to everyone for your help working through this.
Mike
