I oiled my pinewood flooring a few days ago, and now after it has dried up the flooring is skewed. It bends up close to the edges, on both sides of the room. Each plank is straight lengthwise. It's the joints that seems to cause the problem. The flooring lies freely upon a concrete surface. One of the walls is concrete while the others are drywall / plasterboard. The concrete wall is on one of the sides with a single board all the way over (and not a side with many edges).
Before oiling the floor, the skriting was nailed to the drywall on three sides, and into the floor on the concrete walled side.
Now I'm afraid the nails in the drywall won't hold, and nails in the floor on the side with concrete isn't really an alternative, as that won't make it stick to the ground.
Does anyone have a suggestion as to how I can fix this?
The first picture below is how it looks now, while the second one is how it looks if I hold the planks down to the ground. As you can see, there is big difference.