We just bought a house and had the garage door taken out and put in a slider and two windows. We are anxious to get our "family room" done. We want to stain the concrete floor. It is a new construction home. How do we prepare the floor with acid wash without damaging the walls and trim? how much rinsing do you need to really do? We can't just open the door and push broom it out since we have already taken out the garage door! HELP!!