new lawn on compacted clay
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 50/50 split of stone and paved.
So 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 flags. I can also see from level of neighbours garden area that previous owner has diggered down about 6-7ft to create this space.
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 of stones from stone area are sitting on top of clay and all hardcore remains from flag area.
My dilemma is what is next step after clearing area. I was thinking I just level out 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. Any responses appreciated from novice gardener