I am in the process of creating a lawn at the back of my house. The previous owner had paved and stoned the area. The size is about 30ft by 40ft, it is raised from the level of the house by about 2ft, with steps leading up (see pic 1). It was 50/50 split of stone and paved.
I have removed the membrane and most of the stones from the stone area. I have lifted up all the patio flags and now there is about 4" of hardcore that was supporting the flags. I can also see from the level of my neighbour's garden area that the previous owner has dug down about 6-7ft to create this space (see pic 2).
What this means is there is no top soil. As the area has been dug out to 6-7ft the base is compacted clay. A few stones from the stone area are sitting on top of the clay and all hardcore remains from the flag area.
What is the next step after clearing this area? I was thinking I could just level out the stones and hardcore over the clay evenly. Get top soil for about 6" coverage and then sow seed. Is this enough or do I need to do anything extra regarding the clay? Do I need to consider some type of drainage? After some rainfall I can see a few areas of water that have not cleared after a day. These aren't large areas, just a few puddles.
Any responses appreciated from novice gardener