Eco construction


Permeant slabs

Prompt natural cement offers benefits in terms of eco-construction, particularly where permeance has to be kept (e.g.: wine cellars, old buildings). It is used then to lay permeant slabs. It is not easy to lay slabs with ordinary materials that permit the humidity within a structure to evaporate. Artificial cement offers satisfactory mechanical strength but creates a watertight barrier.

Natural hydraulic lime, which provides satisfactory hygrometric transfer, does not produce sufficient mechanical strength for most uses. Concretes that combine natural cement and natural lime better meet these two requirements. Furthermore, Prompt natural cement limits the shrinkage of natural hydraulic limes and reduces waiting time for polishing for terrazzo work.

Dosage information:

  NHL lime PNC Concrete granulates <15 mm (sand-gravel mix) Tempo
Hemp concrete (NHL 3.5) / PNC 1 bag of 35 kg 1/2 bag of 25 kg 15 buckets 1/2 bottle


Order of mixing so as to optimise the quality of the concrete for use:

  • 2 buckets of water
  • 7 buckets of granulates + 1/2 dose of Tempo
  • 1 bag of lime (35kg)
  • adjustment with water (around 1/2 bucket)
  • 1/2 bag of Prompt natural cement
  • 8 buckets of granulate
  • adjustment with water (around 1/2 bucket)

Between 2 and 5 minutes mixing is required once all the ingredients are present.
Open time is around 45 minutes only.


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Launch slideshow