Minor quick masonry tasks: ridges, framing headers, edges
Two aspects of Prompt natural cement make it a complementary hydraulic binder to ordinary binders (limes and cements). It is a natural cement, similar to natural limes, to which it adds short-term strength and reduced shrinkage while retaining the permeance qualities of walls and elasticity according to mix proportions. But for numerous traditional masonry tasks, straight or mixed with lime, it can provide a quick-setting mortar and the application of deep layers, as required for sealing tiles on ridges, framing headers and trimming markers, executing details for renders, etc. In this case, it is used in a formulation of Prompt natural cement mortar or natural lime–Prompt natural cement mortar.
Natural lime–Prompt natural cement mortar
|NHL lime||PNC||Sand||Open time at 20°C|
Lean mix mortar
Overall dose 280 kg/m3
|in vol.||4||1||15||25 mn|
|in weight||320 kg||100 kg||25 mn|
Medium mix mortar
Overall dose 340 kg/m3
|in vol.||3||1||10||20 mn|
|in weight||240 kg||100 kg||20 mn|
Fat mix mortar
Overall dose 360 kg/m3
|in vol.||2||2||10||15 mn|
|in weight||160 kg||200 kg||15 mn|
Prompt natural cement mortar (in volume):
|Ordinary does||1||1||0.3 to 0.5|
When the mortar is applied in thick layers, it is a good idea to incorporate terracotta elements into the mortar (tiles, bricks).
For making edges, particularly in arch mouldings, the mortar can be applied in two stages. First it is shaped with the trowel and then the float. It can then be finished with a nail float (after 1/2 hour to a few hours, depending on the mortar dose).
Setting time can be adjusted using the retardant additive Tempo.