Saturday, March 2, 2013

Venetian Plaster – Its History and Modern Use



Venetian plaster is enjoying a popular revival with the modern renaissance of Italian wall finishes. These finishes while new to some, possess a lineage dating back thousands of years to the early civilizations of Mesopotamia. Unrefined clay plasters were replaced with a mixture of raw lime and crushed limestone. These plasters were sometimes painted with lime paints or indeed used as a base for more elaborate frescoes.

From the remains of the Roman villas of Pompei and other excavated buildings of the time, we can see how the use of these plasters had spread and changed. The Romans knew the benefits of using burnt lime which was than was then slaked (properly mixed with water) and then left to age so as to improve workability. Much of their techniques have been learned from the writings of Marcus Vitruvius in “De Architecture”. Unearthed in the 15th century it documents the building and architectural practices of Rome 1BC. Walls were plastered with 3 coats of a sand and lime mixture followed by 3 coat of a fine marble dust and lime mix to make a smooth polished finish. Whilst the plaster was wet, colors were then introduced to provide a strong, easy to clean decorative surface.

It was the rediscovery of these practices that gave way to their widespread use in 15th century Venice. The lagoon area of Venice had an abundance of wealth and a newly found appetite for classical architecture. At the time, transporting sand around the lagoon was difficult and expensive, there was also an abundance of waste terra cotta from the brick industry and recycling of old roof tiles. So plaster renders were made instead with ground terra cotta and hydraulic lime to make a highly breathable surface well suited to the damp atmosphere of the lagoon area. There was also a great deal of stone and marble waste, this was then ground, combined with lime to create fine plaster finishes or Marmorino. These were often left white to mimic the stone of Istria (modern day Croatia) which was favored by Venetian builders, or painted with frescoes to mimic more exotic marble. Another favorable outcome for the sinking city was that the weight of the Marmorino was considerably less than the classic Roman style of using slab pieces of stone or marble.

Interest in Venetian plaster diminished from the late 19th century until the more recently with their use by renown architect Carlo Scarpa in the 1950′s, 60′s and 70′s. At the moment there is a worldwide resurgence of Venetian plasters being used internally and externally on public buildings, new offices, shops, hotels, and private residences. Whilst some plasters are now made with synthetic acrylic resins. Many still hold true to the original recipe of lime and marble powder, with the inclusion of adhesives so as to be used on modern building surfaces such as drywall.