This water had been standing on this roof for about 72 Hours with no Leaks underneath. That's because of good application of quality Water Proofing materials (thanks to Fosroc) coupled with skilled Labour.
The life of the house got extended by at least 20+ years by taking care of this water proofing. This along with the minor repairs, was part of the Renovation that we did to this 40 year old house.
We then protected this layer with some good tiles, preferably ABC Tiles (for reduced loading).
Water is a great friend of the building during construction but post construction the same water can become an enemy - water entering inside the roof can easily corrode the steel inside, forcing a Renovation. Prevention is better than Cure. Taking care of the Terrace during Construction saves a much bigger cost later during Renovation!