hdb的话好像是上下楼各一半, EC就不懂了, 协商解决吧
http://www.hdb.gov.sg/fi10/fi10324p.nsf/w/HomeMaintCeilingLeaks?OpenDocument
Under the Lease, lessees of upper and lower floor units share the responsibility of maintaining the party structures, including the floor/ceiling slabs. If the cause of the ceiling leakage is due to the wear and tear of the waterproof membrane/screed in the floor slab through usage over time, the upper and lower floor lessees sharing the use of the slab, are responsible to jointly arrange for the repair works and share the repair cost.