There are regs that determine how thick the plastic on the floor has to be and even how thick the trash bags have to be. 

As well as part of the crawl space had no plastic tarp covering the dirt. 

The poly or plastic style nice base (not the office style rolls, but the decorative residential style) is probably your best bet.  

Find something decent you can get at a nice discount that doesn't require major surgery.

He said that when he was in his fraternity, the had a "Florida Party" where they put a bunch of sand on the floor, and then strung up plastic sheeting between two half walls and two 2x4 walls they built for the party and filled it with water.

After a devastating year of open heart surgery and divorce, my savings has been plundered.

I bought some a few months ago for a rental on sale and installed in two bedrooms over concrete slab with plastic sheeting underlayment as recommended.

Is the crawlspace treated for moisture (usually pea gravel and plastic) Is there free airflow between the crawl and the basement? 

My problem got a lot better with some scrubbing with a plastic bristle brush and some ajax powder bleach, but its not totally gone yet.

Ned Carey Priority envelopes are bigger envelopes with a plastic front..