My new-to-me 40-yr-old house in PacNW has a 36-48" high crawlspace that didn't have nearly enough vents and in the warm weather the dank/musty odor comes into the house. I just had existing vents enlarged, 10 more installed, a fan put in, and it's been a huge improvement. Next week I'm having the crawlspace cleaned out, mildewcide/fungicide sprayed everywhere, and a new vapor barrier put down. The extremely clayey soil is dampish looking, but not actually wet.
Would there be any additional benefit to putting in a 1 or 2" layer of sand under the vapor barrier? The downside might be if I ever needed to pump out water the sand might making pumping difficult, I suppose. Any comments?
Sheila