I'm looking to fill and level our backyard. There is currently a 1ft drop off from the patio and the entire yard is sloped.

There is a house a few streets down, where the builder is blasting ledge to build a new house. He has offered to fill our yard with the blasted ledge (we pay for his labor, he gives us the fill for free). He would then put 3" of loam on top of the ledge.

I'm not sure if this is a good idea. I'm worried that the ledge would leave large air pockets for the loam to fall through. Am I better off using something finer, like gravel or sand to use as the base layer instead?

Many thanks!