Spraying mortar is an integral part of building a house. Indeed, plaster is a topcoat that helps protect the walls from the elements while allowing the house to breathe. In addition to its wall protection function, the plaster also plays an important role in the thermal and sound insulation of the building. Its uniform color, which is often clear, brings a pleasant aesthetic to the home while reflecting light.


The different techniques
Plastering can be done according to 4 techniques: projected, scraped, crushed, floated. The chosen technique depends on the desired rendering.
Projected plaster: This is the most used technique for the protection of large buildings because it costs less than the other techniques. It consists in projecting the material using a special machine.
The implementation is particularly fast for a raw rendering.
The plaster scraped: This technique takes the previous one but adds a second step: the concrete is projected and scraped either with a ruler to scratch or with a nail trowel. The implementation is logically longer than in the projected technique but the rendering is more uniform. The tools to be scratched make it possible to eliminate any surplus material.
Crushed plaster: This technique like the previous one requires two steps. The first phase is to project the mortar on the wall and while the material is still fresh, a smoother is passed over the mortar to crush it. The effect obtained is quite aesthetic since the wall takes on an uneven moire aspect.
The plaster float: This technique is most often used by traditional masons craftsmen. It consists in projecting the mortar on the wall then to the float to obtain a smooth rendering. The disadvantage of this technique is that it takes a long time to achieve and therefore costs quite expensive. The walls made with this technique must be completed entirely in stride under pain of seeing large differences in nuances once the whole has dried.
Pre requisites before plaster
Whatever the chosen technique, plastering should not be done immediately after the completion of the construction work. A delay of one month is recommended so that the masonry has had time to dry and stabilize. The walls must be perfectly clean: closed cracks, treated mosses and molds. These precautions are even more important when you are renovating.
Plastering must be done under specific climatic conditions. The temperature must not be greater than 35 ° nor less than 5 °. The substrate must be moistened if the temperature is too high to avoid cracking and detachment of the plaster.