I have 3/4" oak tongue and grove floor, 5 years old, laid over concrete that had plywood laid on top of that. The moisture barrier according to the installer is the glue. I had a slab leak last week (hot water) that I suspect had been brewing for a long time but we just figured out the problem. Of course it's in the dining room and we had to take out a 18" x 18" section of the floor to fix. It took a while to discover because the floor never felt wet, I discovered a lower lying closet (carpeted) had about 1/8" of water in it.
ANyway we did have the plumbing leak fixed and now my floor is a mess. A few sections have buckled which obviously need replacing. Part of the floor has some cupping, part of which I've had for years and was too dumb to know that this was a sign of moisture beneath the floor. I called my installer (this was a sub-contractor for a whole house remodel) and he said to run fans and call him in a couple of weeks.
I have a few questions.

1. I rented a dehumifier to go along with the fans because I live close to the ocean and the air is quite damp. How low should I dehumidify the air? Currently the RH is around the high 30s after 3 days of running the dehumifier. My house temperature is around 76 and believe it or not that is without running any heat, we've had a heat wave in So. California. In fact I rarely use the forced air heat and don't have AC (don't need either really.)

2. Is it possible to lessen the cupping? Are there any special do's or don'ts?

I don't plan to turn it into insurance (long reasoning but anything short of the house practically being destroyed doesn't warrant it, it's too easy to get cancelled and have trouble getting new insurance.) I want to save as much of the floor as possible for financial reasons and I love the floor.

There was never any water standing on the floor, just moisture from beneath the slab leak. Any advice is appreciated.

Listen to your flooring contractor. The flooring needs to dry but over drying isn't good. You will need to be patient. This type of repair requires time and a good moisture meter.

the flooring needs to get down below 10% moisture, after that you can safely say its not going to get any better and a resand is proba;;y in order. If you sand it at a high moisture content when it does fully dry you will end up with a crowned floor instead of a cupped floor.

How low should I allow the air humidity in the room to be? It is currently 35. I know that I can't dry the floor too quickly and haven't used any heat but am trying to dry with fans and dehumidifier.
Does anybody have any idea what the room RH should be to optimize drying?
Again we live near the ocean with cool humid air.

Shappys, If your flooring is on plywood and the plywood has been wet, the plywood may never dry know matter what you do to it. We tear these out almost every day and find mold between the slab and the plywood.
The water can wick through the plywood and be very high in moistrue all the way across the room. Check it out.

No matter what you do above with dehumidifiers, it is not going to remove the excessive moisture hidden below the plywood. Removal of the flooring and subfloor, is the only real way, or you could have a serious mold concern later.

Pull all the wet areas up and back even farther. Now get your dehumidifiers going and check the concrete daily for moisture with a Tramex concrete moisture meterm called an encounter.

Thanks for the replies. I got to thinking--the half of the dining room that has cupping is set on plywood, however, it is set about 5 inches off the slab. Your replies reminded me that since there is a gap between the plywood and the slab I could perhaps open the floor up and air it out. So today I drilled some holes and sawed inbetween to open up a hole so there is now some air circulating. The good news is there is no standing water on the slab, no mold on the plywood (that I saw) or slab. The relative humidity of the airspace is over 80%. I have a commercial dehumidifier going and have also put "rid" in the airspace. I can put my hand on the underneath part of the plywood and feel dampness. Hopefully I can dry the area out before mold grows. Perhaps I can reverse the "cupping." In any case the boards that I drilled would need to be replaced anyway.