Roof top garden need advice

We have roof top garden in d17 , but it seem the idea is failing due to heavy rain , tha water stagnated in the grass .
The roof garden is on the half of roof approx 120 yards .

May be the drain system stuck with soil .

May be we need to re-make it with iron frame beneath to allow drainage .. ?

Is there any good contractor who has designed roof top garden ? We want to have grass in full of garden plus some plants .


Any suggestion ?

Dear Z A Shah,

Roof garden is very nice addition to your house but it needs to have proper planning. There are many factors which needs to be focused before you start growing grass. If possible please share what is the current situation.