The popularity of Venetian plasters has surged in the U.S. during the last decade. Driven by European design and architectural trends, typical Venetian plasters made from limestone are softer and create more natural variations than most Portland-based cement and acrylics. Whereas many modern building materials create a flat, synthetic look, limestone finishes have an iridescence and translucency that create a far richer aesthetic to any building project, whether old-world or contemporary.
But looks aren’t everything.
The content of magnesium in the mineral is very important, because it gives the finish coat an immediate abrasion and weather resistance. Due to the seasoned slaked lime’s high pH levels, the river limestone used in Vero-Rialto plasters are considered natural biocides. Therefore, they do not promote the growth of mold. They have a high water vapor permeability, which helps the natural vapor-flow through the walls, reducing the risk of blistering and peeling in humid areas, making it an exceedingly durable and long-lasting plaster finish. Whether rain or shine, these finishes get richer and beautify with age, emphasizing the natural movement throughout its life on the wall!
Vero’s Venetian plaster production process originates in Italy and is produced in a manner steeped in tradition.
- Lime rocks (limestones) are selected from a river in Italy, where they were formed in shallow, calm, and cool fresh waters. The smaller limestones are separated to obtain a load of similar size to create a homogenous cooking of the stones.
- Limestones are then taken to a 100-year-old kiln, which is fired with sawdust from nearby furniture manufacturers. The heating is a very slow process, typically seven days at an average temperature of 1650°F. During the heating phase, the calcium carbonate and magnesium release the CO2, and the stones lose 1/3 of their original weight. The stones become calcium oxide, known as quick lime.
- The lime rocks are sorted again from the overcooked stones, which are used in creating statues and mosaics. The quick limestones are slaked with water, and turn into a liquid slurry made up of water and fine lime particles, which eventually turns into slaked lime or lime milk. Once slaked, the lime is distributed to separate seasoning pools for two years or 24 months. This turns into Grassello di Calce, “grassello” meaning fat, a creamy like substance that is the Ferrari of building materials used to create Vero-Rialto plasters.