answer:First, good not doing it now. One house the painters assured us the epoxy would be just fine putting it down in the cold weather, and it wasn’t. I would probably just use cardboard, but that’s not from experience, just a gut feeling. If you use a tarp, or anything, maybe on the weekends pull it back to make sure the cement gets dry each week. Also, even if it does get a little dirty, I think when you etch it with the acid it will be fine. I have had neighbors epoxy their garage after owning their houses a couple years.