Travel-trailer owners know to block the back of the tire while parked at their campsite. Those who live and breathe RVing know to block in the front AND the back of the tires. Weight distribution through-out the camper will shift while you are enjoying the amenities of your home on the road. If the weight happens to be concentrated in the rear of the camper, well the front may pop up and you might find yourself taking an unplanned tour of the campground.