Hess Pumice Ultrapozz Pozzolan 22.6kg


A highly effective natural pozzolan with extremely fine particle sizes. Pozzolans have many uses but they are primarily used to react with calcium (in cement or lime), but also may react with other minerals in earth and clay.

Pumice pozzolan is unique in that is it a bright white colour and therefore does not discolour lime or white cement.

1 bag is 50lb or 22.6kg

Out of stock



  • Lime Plaster: Creates a hydraulic lime from hydrated lime without altering the colour. Makes the plaster denser and less permeable compared to hydrated lime, but sets quicker. It is most commonly used for exterior lime plaster where strength and durability are more important than vapour permeability. Use at 10-50% replacement of lime.
  • Concrete: It makes the concrete denser, stronger, less permeable, more resistant to chemical attack and less susceptible to freeze-thaw cycles. UseĀ 15-20% replacement of cement in concrete.
  • It may have a pozzolanic reaction with clay and could be used in the same way that it is for lime plaster.

It is mainly amorphous silica (and doesn’t contain any crystalline silica) and therefore much healthier to work with. Using a respirator is still recommended.

Weight22.6 kg

Hess Pumice Ultrapozz Technical Data Sheet