Tony Hwang wrote:

Todd wrote:

Ok, I plan to cover the dirt in my crawlspace with plastic, as a
temporary measure to reduce humidity down there. Yes, I realize that
this is not a permanent fix, and yes, I realize that I need to address
the source of the moisture problem.

Here is my question: Do I need to treat the dirt with a chemical spray
first, before laying plastic? If so, what chemical? I am thinking
that if mold/mildew is a potential problem, that something nasty could
happen to the dirt if it is cozy in plastic for the winter. Opinions
please...

Todd
Hi,
If you lay plastic sheet down, the mositure will be trapped underneath
and it may get worse. One thing missing down there is good air
circulation probably.
The crawl space out at my cabin is dry year round. Dirt is dusty dry all
the time. I have a hot/cold air outlet from furnace going there and
walls are insulated to R20.
Tony

Whoa Tony. Trapping the moisture underneath the plastic is
exactly the purpose of covering the dirt with plastic. BTW,
it isn't dirt, it is soil. You don't want the moisture
coming into the crawl space from the dirt.