i'm planning to add some fill to my yard to get it a bit more level. i got 12 yards dropped off for free from craigslist, but as i was shoveling, i noticed it was quite clayey. there are intermittent baseball-to-basketball sized clumps. the rest of the soil is probably clay, but not bonded as well (yet?). anyway, my concern is that if i spread out the 12 yards, that now i will have a water resistant barrier. i'd like to amend the soil, but on the cheap. i've read that in order to do it well, you basically need >50% sand added to it. that's not happening (too much $). i also read that you can use gypsum, so that got me thinking: what if i use demo'd asphalt chunks (2" diameter max)? i will be demoing a small bball court in my yard in a few weeks. i can recycle it for a reasonable price, but if i can just use as fill, that would be way easier. do you think this will work? likewise, i can probably get free woodchips delivered too. would those help? ultimately, the top layer will be topsoil from a nearby supplier, so the grass should grow well. i just don't want a soggy yard for 6 months of rainy season.