We have a vinyl floating floor. When installed we used an 8 inch oak plank as a stoop between the kitchen and family rooms as the floors were not at the same level (old and new construction). The drop is about 1/2". The problem is that the floor is shrinking away on one side where the board met the floor but did not overlap. So we have a gap. I have tried caulk but it was unsatisfactory. I have thought of a wider plank, beveled on both sides. Any suggestions would be helpful.