Some background: I live in the Raleigh/Durham area of NC. We have thick clay soil and tall fescue. It seems that the builders just laid sod on top of the clay soil, so the only "topsoil" is that which came with the sod (only an inch or so). Since the topsoil is so thin and the clay is too thick for the grass roots to go into, the grass doesn't grow very well and needs to be overseeded constantly. Many people suggest that if you have thick clay soil (which I do), adding compost as a topdressing to it once or twice a year will eventually build the soil up over time (giving the grass roots more room to grow). But in "Sticky: FAQ #2 - How are they used (pt 1)", there is a statement: "Compost is a material that will be completely digested in a year or two leaving no depth to it. So 4 inches will become zero inches. This is an important concept." This seems to go against what I have read elsewhere. So which statement is correct? Does the compost build up the soil over time? Or does it fade away into the sunset?