How do they jack up big coach when replacing tires?

I wasn't happy about it but the place near Decature,Ind jacked ours up with the leveling jacks. He blocked the tires on the rear first and of course air brakes were on. It semed reasonable after thinking about it but. When they pulled the rears hear lately they use air over hydraulic jacks similar to the ones we roll under a car. Have to be careful of where you place them. Definately not on the axle tubes, or differential.