Difference between basement planting tops and non-planting tops

There is a difference between the basement planting top plate and the non-planting top plate water retention capacity. Basement top plate is equivalent to the floor of the first floor floor, the basement floor is equivalent to the foundation floor, generally speaking, the floor is specifically referred to the bottom layer of the ground (reinforced concrete cast-in-place floor) the rest of the floor are generally referred to as the floor. Non-planting roof due to roof greening need to backfill the soil on the roof before planting plants, so its soil layer is bound to be relatively thin, plant root growth space is limited. Garage roof often has a large height difference with the ground elevation, so that most or all of the roof backfill soil is not connected to the natural soil on the ground, the source of moisture is limited, and the water retention capacity is also poor.