Thanks. Well if the gaps are on one side of a plank and the other side is normal, don't you think the movement can still happen? Here is one trick someone told me about: Take natural rope, and glue into the gaps, then finish over that. But that sounds to me like it would act much like a silicone. I was reading on some Gym floor finish at Menards, that it says it will move with the wood. If that is true, then can't the gaps be filled with it?