wpc foaming floor is made by extruding or co-extruding ,lighter and stronger, ... encrusted foaming.3,Its water-proof,anticrash,flame retardant(pass B grade),anti-corrosion,UV-protected,sound&thermal insulation and energy ... ,grounded in dirt or rust stains become a problem, a cleaner that has Oxalic or phosphoric Acid Base may be used ... ,but it could cause slight color variation. outdoor wpc foaming floor