Can anyone give me an idea of the layers required for embedding PEX tubing in a driveway using concrete pavers? Without the PEX, I would need a 12 inch base of gravel, then a 1 inch layer of bedding sand. I would assume that the PEX would go into the sand layer, but where would the foam insulation go, between the sand or below the gravel base? How thick should the foam be, and wouldn't it crush under the weight of cars, leading to an uneven paver surface?
Thanks in advance for any advice!