In cleaning occupations, about 80% of all cleaning tasks are done by manual cleaning tools, and about 30%-35% of working time is spent on mopping floors. Cleaning is considered as a physically demanding and strenuous job. This study examines the effects of mopping on polished and non-polished linoleum floors in school classrooms in terms of muscular activity and subjective awareness. Ten professional cleaners volunteered for this study and surface electromyography (sEMG) was recorded from six muscle groups; left and right wrist extensor, right and left anterior deltoid and right and left upper trapezius. The cleaners were randomly assigned a type of floor to be used in each test. The cleaners performed the mopping task for both polished and non-polished floors at their normal working rate. The results show no significant difference (p<0.05) in muscular activity while mopping on the polished floor compared to the non-polished floor; however, the cleaners rated the polished floor more comfortable to mop.