There is a crawl space under my uncovered front porch. The walls seems to be a mixture of cinder block and brick. The crawlspace "ceiling" is a cement slab and the floor is dirt. The floor right now is covered with various bits of rotting wood. The floor is level with the sorrounding ground. There is one small vent in the wall and a rotting piece of plywood as a door. The space stays pretty dry and we would like to use it for storage of things like bikes, yard tools, and maybe even window AC units.
I am in Washington DC so we get below freezing tempratures, but I was still hoping to just do a pour over the roughly graded dirt to keep things cleaner and make moving things easier. Is this feasible? Given this is truly "outdoor" space without any house above it, would I need a liner?