The first and foremost thing that you need to take care of is to build a terrace that does not allow water to accumulate and form puddles at places.
Tell your renovation contractor in Delhi to take care of that. The slope of the terrace should have an outward inclination. If your renovation contractor in Delhi has not taken care of that, water will get accumulated at places.
This will in turn damage the floor which leads to the dreadful problem of water leakage. Tell your renovation contractor in Delhi to make a hole so that the remaining water passes away as proper drainage is very essential to avoid water leakage problems.
There should not be any crack on your terrace. If possible, go for a ‘waterproofing coating’ on your old terrace. If there are any cracks, it will cause water leakage problems which in turn will damage the steel or metal structures of the building.
Once the steel or metal surfaces are exposed to water they will start corroding causing expansion, hence weakening the whole structure.
The concrete slabs will no longer be held firmly, as it was before, therefore destroying the whole structure. Do make sure that the pipe that runs through the roof or the parapet wall is of good quality. Don’t use any local ones, that are easily available in the market.
Go for branded ones; and don’t forget to do your research online before jumping to any conclusion.