Here in the southeastern U.S., we have a lot of crawl spaces. Most are vented. Even most new ones are vented. It’s not because it’s the best way to keep them dry. That’s certainly not true. We have enough research on crawl spaces to know better. No, they’re vented because foundation vents got into the code decades ago and, once there, they’ve been difficult to dislodge.
So if you have a vented crawl space, especially in a humid climate, it most likely has moisture problems. And where does that moisture come from? Let’s take a look.