insulating freezer floor

[santa fe]

Can a cooler with a 6" concrete floor and no other floor insulation be converted to a freezer application without removing the existing floor?
Is it enough to insulate over the old floor and pour a new floor on top of the insulation? And how much insulation is adequete?
Moisture barrier?

[terrygoodrich]

You can do this with a minimum of 4 inches or 10 cm of Foam insulation board. If the dimensions of the freezer are very large, say more than 12 Ft. or 3 meters across there may be danger of freezing the ground under the center of the slab. In which case a small heat source must be placed under the insulation such as electric heat cable to prevent the earth from freezing under the concrete. A vapor barrier should always be installed on the warmer side of the insulation. In this case, it would be placed under the insulation.