Abstract: Surface treatment apparatus having impact elements for impacting a surface to be treated, a brush element for brushing the surface, a drive device for operating the impact element and the brush elements, and a carriage device enabling the surface treatment apparatus to be moved across the surface to be treated. The brush elements include a composite rotary brush assembly having circumferentially spaced rows of bristles mounted on a rotatable shaft in alternate circumferential sequence with the impact elements and further rotary assembly mounted on a contra-rotation relative to the composite rotary brush assembly and/or the impact elements, each rotatable so their bristles move upwardly intermediate the respective shafts. The impact elements include a plurality of longitudinal spaced hammers each pivotable about an axis substantially parallel to the axis of the rotatable shaft.