Dosages and advice

The exact proportions depend on the chosen dosage and the nature of the sand. To obtain a precise volume of mortar, use the online calculator that integrates the bulking and density parameters according to the application. At the standard dosage 1-1 by volume, to obtain about 10 litres of mortar, plan for about 5 litres of natural Prompt cement and 5 litres of dry sand. The volume of mortar obtained is slightly less than the sum of the constituents, because the cement paste fills the voids between the sand grains.

The quantity of water depends on the dosage and the desired consistency. For a mortar at the standard dosage (1 volume of Prompt + 1 volume of sand), 0.3 to 0.5 litres of water are needed for 2 litres of Prompt + 2 litres of sand, depending on the desired consistency. Excess water reduces the final strength and disrupts the setting. The water must be clean and at positive temperature, poured progressively into the batch. In hot weather, use cold water to control the setting speed.