How much vermiculite do I need?

Bags of Dupré Vermiculite are 0.1m3 in volume. The simple rule of thumb is that 1 bag of Dupré vermiculite will cover 1 square metre to an approximate depth of 10cm. Bulk Bags of 1.2m3 and 2.2m3 are also available. Other packaging may be available on request.

Volume Calculator


How Heavy is Vermiculite?

Loose Bulk Density of Vermiculite depends upon the grade of vermiculite.

Does Vermiculite Contain Asbestos?

No. The Vermiculite that we use in our products and the Micalite Boards is checked by an independent laboratory for the presence of Asbestos. Asbestos has never been detected in our product. Vermiculite is sometimes associated with Asbestos because of an incident that took place in Montana, USA. The asbestos found in the material from Montana was not due to the vermiculite but to the presence of another mineral called diopside.

What is the mixing ratio to mix Vermiculite with Cement?

Typical Use Chimney Filling
Mixing Ratio by Volume 6:1
Materials to place 1m3 of concrete Micafil Vermiculite 12 bags
Portland Cement 12 bags*
Water 276 litres
Smaller batch mixing Micafil Vermiculite 1 bag
Portland Cement 1 bag*
Water 23 litres

What are the insulation properties of Micafil

Insulation Data

Thermal Conductivity: k-value = 0.063 W/mK
Thermal Resistance: R Value: 16.1 m2K/W per metre of insulation.
Thermal Transmittance: U-Value: This is the overall rate of heat transfer. To correctly calculate a U-value, all layers of insulation must be included and not the vermiculite layer
alone. The calculation requires the R-value for each layer (for R-value of vermiculite, see above) and also constants accounting for surface transmittance from
the inner and outer surfaces (Rsi and Rso) and also for a small standard air gap (Ra). This calculation is often performed with specialist software and is not
elaborated upon here.