Would this be a basic recap of you idea?: Instead of adding a heavy layer of clay, your hopes are to add a little less thickness in clay than a normal procedure. In exchange for less clay you want to add in a layer plastic.
Clay works by binding/knitting together (with a sheepsfoot roller). Pond builders seem to have come up with a number of inches that this works best at. Where I am going with this is if you separate these thicknesses with a layer of plastic will these layers effectiveness be diminished so much that the benefit of adding plastic is negated? I can't answer that, just throwing it out there for consideration.
How many inches of clay of packed clay underneath the plastic is your goal? How many inches of packed clay on top?
