Why not 4 inches of sand over heavy sheet plastic??
A little story of my house in York Haven - The area under the two kitchens (28 x 16) is a semi-crawl space, closed in, no vents, no windows. The house is a "semi-detatched", but there is no division between under the kitchens as there is for the main 7/8 cellar and the neighbor has no separate access for his half of the space.
So about three years ago, in an exploring mood, I removed the access plywood and discovered the sweetest dryest air in the crawl space under the kitchens, it was wonderful!! A cheap 24' ladder, some old oil cans and a 30' long board were stored there, for how long, God only knows. There was no rust, and no rot ! Only the York County, PA clay soil, and decent access to the water and gas lines and lots of storage space for the packrat !

Hi,

Tauton has an excellent book on insulating homes that describes their using 2" polystyrene boards against the foundation for insulation, and then sealing continuous 6 mil poly sheeting to that.

The sheeting and insulation form a vapor barrier that will also stop the damp earth smell. Their main reason was to be able to close off the venting to the foundation by making the crawlspace a part of the house's "conditioned space." Not having cold air in the crawlspace makes things a bit warmer. They didn't heat it or anything, just closed off the dirt and outside air.

Local ordinances may differ ;-)

Personally, I think it is a sound idea.

First you need to fix the wet crawl space problem. The crawl space should be bone dry, and chances are the landscaping around the foundation perimeter is to blame. It should slant down all round the home for at least five feet. The roof should have gutters, and the runoff directed away from the foundation with runoff ramps.

Doh. I don't believe I missed the nuddy part.

Sounds like it could also be a broken drain pipe.