i guy i know, he made some changes to his property. one area that was originally a blacktop driveway, he tore up, and laid sod. here is the problem: the driveway was like 3 layers thick! it looks like there was a walkway there many years ago. somebody paved blacktop over top of it. somebody then paved another blacktop driveway over top of that. so, most of the blacktop was removed, this still leaves a layer of concrete, or blacktop, but now there is enough room to put in like 6-8" of topsoil. will the sod live? i don't think so. what do u think?