My pad is 30' X 12' X 4" 4000 psi concrete/fiber added on an 8" class A base of gravel. It has been in place now for four years and has never moved or cracked. Because my MH overhangs the pad on the rear I layed down some patio pavers to keep the moisture away. The pad makes an awesome surface for doing your own maintenance.
Binnie, Wanda & Yasper (Labradoodle)
1999 Winnebago Chieftain 35U F53 Chassis V10
Towing 2014 Jeep Wrangler Sahara