I would say the chances are that the roof terrace is common property and therefore it won’t be covered by your insurance.
Unless the building is less than six years old, it won’t be covered by home warranty insurance and I doubt if whatever building insurance your Owners Corp has would cover something that probably comes under normal wear and tear.
Too many imponderables. Establish if the roof is common property – it probably is – then ask the Owners Corp to fix it.