Crawl space circulation and venting help.

[yeldogt]

Everyone likes to jump to "seal the space" right away, but forget that houses have been built in the south with vented crawlspaces for hundreds of years and performed perfectly fine with moisture.

When you seal the crawlspace, it then must become a conditioned space per code, and if you have any makeup air pulling from there, you will have to deal with that too. Then you also have to deal with opportunity for condensation now at the outer walls.

Something has changed with the amount of ground water, figure that out first.

With a pier house and no insulation or AC -- the structure can absorb and release moisture. it's going through cycles.

Once people start to condition (AC) and partially close up a crawl it no longer can ... houses and construction evolve. We start to insulate -- HVAC equipment etc .. that's when things start to change.

Most houses don't have insulated floors -- so in hot climates today they are colder than the surrounding air .... the same occurs in attics in cold climates (hot air from the dwelling brings moisture into the attic) both cause condensation.