my dogs large water bowl sat next to an inside wall in my kitchen on a linoleum floor. I guess over time from water spilage, the water ran between floor and baseboard. My wife noticed the floor was "spongey" in this area. when I got up under the house(crawl space), I found that the moisture was contained between two floor joists, the isulation was wet, but no dry rot noted on the joists or sub floor. the dog bowl scinerio is the only explanation I can come up with. there are no water/drainage pipes leaking under the house that I can see. ground is dry. space above wall is unfinished bonus room, no water up there to leak down through.
How can I best dry this out? toying with ideas of heat lamps under house, electric heaters?
I'm suprised that if you can actually get up underneath the affected area that the natural airflow doesn't take care of the problem for you (once the dogs bowl has been removed)
I would recommend you check all airbricks are clear around the house so that a flow of air can circulate around your joists to remove any condensation, also check that there isn't anything bridging the gap between the joists and ground such as building rubble etc. as this could give you rising damp.