I've seen cases where the warm moist air condensed on the underside of the roof sheathing and rotted it and the rafters.

It has exposed floor joists and exposed underside of hardwood flooring of the first floor apartment.

Underside of house is immaculate, without cracking or for of any kind.

Good update @Justin R.At least you don't have a dumpster of stuff to clear out of there - you're already a step ahead.Don't forget to check the underside of the home for problems too.  

Buckets of moisture are migrating up out of the soil into your investment(lay a 2' x 2' piece of clear plastic on your lawn in the middle of summer and watch how quickly water droplets form on the underside). 

You might already know this, but: do the dishwasher drain hoses go up from the dishwasher, to either an air gap or the underside of the counter, before going back down to the sink drain or Disposall connection?

If there is access to underside of its floor and it's wood I would Try drilling and spraying a few cans of Great Stuff expanding foam thru the floor and see how that works. 

Adding acoustical insul between the floor joist to the under side of the floor works so.

You could drill a small hole on the underside and let any standing water drain, then when dry, you could put the cap on.

Have to insulate the attic in my duplex (frost forming on the underside of roof causing a leak).