Why Is It Cupping Now?

Another fine week of crawling and sweating. I know it may be petty in the grand scheme of things, but I wish they would put crawl space access doors closer to the hardwood floor area. This house had carpet in most areas except for hardwood in the living room. The hardwood was cupped in this several-year-old house. The cupping was new this summer.

So I checked things inside the house, donned my Tyvek suit (and started sweating like crazy) and started crawling under the house to see the underside situation. Here's a picture of this crawl space. If you look close, you can see water droplets on the insulation:

This crawl space had been wet for years. The owners added vents and a ton of fans in previous attempts to dry the crawl space. Here's a photo of one:

But when you blow humid air around, all you do is blow humid air around.

One of the things I have realized in an existing house is that when something happens, something else likely changed at about the same time to cause the situation. This floor didn't cup last summer, but did this summer. What changed? Sure, the weather is a little different, but not different enough in my opinion. So I asked questions. What changed? I finally found out that the homeowners had changed the thermostat on their AC system to a programmable one so they can run the house a little colder at night. The extra cooling in the house was enough to push the crawl space over the edge. Now we can get things down there dried out some, and get this problem addressed.