On Sat, 23 Apr 2016 15:01:46 -0700 (PDT)
Fredd Wright wrote:

I have a crawlspace in the basement that has a dirt floor right now.
I'd like to lay some sheets of 4x8 plywood (or other material) on it
to make a surface suitable for crawling on or putting things on. It

maybe first install a sump

then maybe a layer of large gravel

then marine plywood

then store stuff you do not care too much about as it will corrode
in that environ