The city has already been hit with walkouts at its airports and some of its swimming pools, but a union spokesman said next week's strikes will affect rubbish collection, water administration, the health clinics and the swimming pools again.
Berlin newspaper BZ reported that the union wants a 6.5 percent salary increase for its rank and file and a minimum wage of at least €200 per month.
Trainees should be paid €100 more and receive a guarantee that they'll be hired after a successful completion of their traineeship, according to the union's demands.
The public employers are offering a 2.1 percent salary increase beginning in May and an additional 1.2 percent for the following year.
Warning strikes earlier this month in Lower Saxony hit the Hannover area during the CeBit technology trade fair. The walkout resulted in city officials asking residents to give visitors a ride in their cars to the trade fair, as public transportation was disrupted.