Often, the irregularities of walls do not allow the establishment of paint or wallpaper. Moreover, lime is a natural product, environmentally friendly.
So it is ideal to use lime plaster, particularly aesthetic.
The lime plaster is able to applied on all mineral granular materials (not wood, old paint lacquer and avoid plaster). First, You must brush the wall to clean and humidify it the day before the site, enough to be wet the next day.
Warning: it is imperative to wear gloves because the lime is highly alkaline and irritates the skin.
Use slaked lime (NHL) for a quick decision.
A coating includes three layers:
For interior decoration, only two layers are sufficient.
It is thrown roughly trowel then floated if the wall shows irregularities. Its thickness varies between 5 and 10mm. It is richer in lime and thicker sand.
Provide 35kg of lime for 80L of 0-5mm sand.
Make a pile with sand, add the lime and mix with a shovel. Then make a hole in the center of the pile and add water gradually until the desired consistency according to the layers.
To find out when the coating has a good consistency, You can knead into a ball by hand and drop it. If it does not fall apart, its plasticity is quite correct.
Counting 2.5kg /m² of lime for 5mm thick.
It is the finishing coat applied with the wood float, which will be of a thickness of 3 to 5mm. It is less rich in lime and made with finest sand.
Both applications are “wet on wet”, the day after the previous layer, after having moistened it.
Only the top layer can be clamped to the trowel for a smoother look.
Provide 35kg of lime for 110 to 150L of 0-2 mm sand.
Counting 1.5 to 2 kg of lime /m2 for 5mm .
It is of course possible to use the colored lime or natural pigments to add color to the coating.
For more details, download the excellent instructions in the CAUE Vendée.