we moven into a mobile home in 7/99 and the particle board flooring was already raised above the floor under the furnace central h/a unit. every time we turn on air conditioner it drips water from the furnace opening. question is why does the partical board swell like that and why did it fall apart under the vinyl floor cover. Also is it normal not to have some type of support under this kind of flooring ? thanks anything you can tell us about particle board would be helpful. Thank You S. Lemay