cleaning and sanitation services./ maintenance cleaning/glass and cleaning./ lot 1: the contractor has to ensure the cleaning of the interior of the building at the client's 4 locations in mayen, weißenthurm, andernach (2 buildings) and bendorf. the cleaning must take place monday to friday after the end of the client's working day (from 4 p.m.). lot 2: a two-sided cleaning of the glass surfaces using suitable glass cleaning agents. furthermore, the entire surfaces must be cleaned by adding a suitable agent. cleaning has to be done twice a year. the first cleaning of the year has to be done in april/may. the second in september/october. the exact dates are determined in consultation with the client.