Any time nowadays I lay plastic down before I pour concrete, cheap and effective way to stop moister wicking. What I see in the pictures does not seem to be the case, cement has a light tint to it...looks good to go. I would take a trip to an Menards, Lowes, Home Depot and choose a dehumidifier, don't cheap out here. As mentioned before, they can freeze up and the cheaper ones will...the nicer ones have a heating coil built in to prevent freeze ups...Once you get your garage dried out, this will help you determine what direction you want to head with your insulation....
The builder layed a vapor barrier (thick plastic sheeting) on top of the gravel and re-bar wire before the concrete was poured.
Isnt that enough to seal?
