Abstract: The invention is a riding floor polishing and grinding machine that uses one or more gangs of polishing heads (242) to treat concrete and similar surface flooring (208). A compact vehicle (210) equipped with a front loader arm (235) is fitted with a module (240) containing the gang(s) of polishing head. The vehicle (210) is capable of raising and rotating the module to easily change the pads attached to the polishing heads. Each polishing head is individually powered by a motor and floats over the floor surface. The pads attached to the polishing heads can be of many different types, preferably diamond-impregnated polishing pads. The invention enables operator to more quickly and efficiently remove material from a floor surface. The design also enables gangs of pads to be mounted with different grit ratings to perform different treatment operations using a single machine in a single pass over a floor surface.