We have lost alot of our insulation over the years under our mobile home (1974 model, very old, & it just the insulation keeps falling down) & since we have had alot of rain over the past few months here in S. Georgia we've noticed that our floor in areas of our kitchen is beginning to sagg between the floor joists. We are in an old mobile with particle board under vinyl as flooring. We know that loosing the insulation has caused the problem, but we need help as to the best way to replace what we are loosing. If we remove the vinyl & let the underlying wood dry, can we fix it by putting plywood over top, or do we need to replace it all? We are on in our years & don't have alot to spend so whatever help or suggestions we get would be much appreciated in the cheapest way possible would be greatly appreciated.