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Vermiculite Lightweight Concrete: Insulating Concrete with Polystyrene Ventboard

This system of superior insulating value consists of polystyrene board and vermiculite insulating concrete applied over structural bases of regular concrete, metal or wood. This system provides flexibility that will meet most design criteria. Insulating values can be varied by changing the thickness of the polystyrene board. Proper slope to drain can be obtained with the vermiculite concrete. Minimum thickness of the concrete shall be two inches.


  • Add 6 lbs. per sq. ft. for built-up roofing.

  • Ceiling used in "U" value calculations is 1/4" Fiberglas lay-in panel.

  • Authority for "U" values based on ASHRAE Guide and test data by recognized independent laboratories.

  • Weights and "U" values may vary slightly dependent on corrugation depth variance of each sheet manufacturer.

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