When I first began to learn how to plaster, if someone would have told me then that it would one day become necessary for me to learn to speak Italian, I would have chuckled and turned away.
For more than a decade, a unique and beautiful style of plastering has grown from a very small niche market into a major decorating accoutrement. It is often referred to as “Venetian plastering” or “Italian finishes” and identifiable by its rich, vibrant mix of colors and/or a highly polished, marble-like, surface. The style of plastering is intended to imitate wall finishes found in Italy.
Centuries ago, in the architecture found along the canals of Venice, builders wanted to achieve the beauty and elegance of marble, but they had a problem. The structures along the famous canals have a tendency to sink, and layering large heavy slabs of cut and polished stone on a building makes them sink faster. So they devised a method to coat the base plaster with finishes that imitated real marble. The finishes were made of well-aged slacked lime and sometimes the addition of very fine marble powder was added. You see, the chemical composition of marble is CaCO³, or calcium carbonate, which is also the chemical composition of lime. Marble gets its color and striations from impurities such as clay or iron oxide. From the earliest records of plastering, such natural materials were used in the coloring of a host of plaster finishes, and by adding them in just the right amount and applying the material in just the right manner; one can imitate marble at a fraction of the cost (and weight).
Most of the original finishes were applied in a manner designed to show off the highly polished and silky smooth surfaces. These finishes are called Veneziano and are the style we often see at trade shows because they elicit the “ooh-and-ah” reaction. Another architectural application is the imitation of travertine marble. Travertine is known for its porous characteristics and can be imitated by using a lime finish containing marble dust known as Marmarino. The resulting finish is, not surprisingly, referred to as, Travertino.
Another aspect of these finishes is age, no, not the age of the lime, although that is very important. I’m referring to the age of the plastered wall in Italy that some designer, owner or architect may want replicated. Think about it, a highly polished colored plaster applied three or four hundred years ago and made to look originally like polished marble. Add time, weather, soot from chimneys, water damage, multiple patch and repair jobs later and Walla! You’ve got an Italian look that everyone seems to be crazy over. If you ask me, it looks like a patch job gone bad, but if done with the right colors and in a consistent manner, you’ve got what these folks call Stucco Lugano or Stucco Valentino. Note the word “stucco,” which we use to refer to Portland cement plaster is pronounced “stooc-oh.”
After watching so many of my peers apply these plasters, and listening almost mystified (and maybe slightly annoyed) as the Italian names rolled off their tongues as easily as if they were ordering dinner at an Italian restaurant, I decided to step out of my comfort zone and immerse myself in a week-long class, offered by one of the leading material importers, to see what all of the hubbub was about.
I show up first thing Monday morning, tools ready and dressed in my best pair of whites and meet my instructors and classmates, a custom house painter and a mural artist. I think to myself, “What gives? I thought this was a plastering class.” I then soon discover that while my instructors repeatedly refer to themselves as plasterers, they have never applied cement or gypsum plaster. I immediately got a little cocky and say to myself that this will be fun. Little did I know …
Day one we prepped small rectangular pieces of drywall by coating them with a reduced acrylic solution; the next day most received a coat of primer while others received a basecoat of the Veneziano or Marmarino materials. Ultimately, we used six different materials-some natural lime and some acrylic modified, maybe a dozen different colors. Some of the materials were applied monolithic while others mixed and layered both color and texture. The various color combinations and differing materials achieved 33 distinctly different wall finishes by week’s end. During the process I learned a lot about what I didn’t know.
While it is true that our instructors weren’t “dyed-in-the-wool” conventional plasterers like me, they were knowledgeable, passionate and skillful in what they did know: Italian finishes. And while at first I was somewhat resentful at being in a plastering class with a painter and an artist, we all ended up learning as much or more from each other. While using a trowel to apply these materials is at the heart of the application, what about the preparation? Masking and painting primer is a big part of this job. Understanding how to lay-on material in a manner to create either a perfectly smooth wall or a textured surface is right up a conventional plasterers alley but can you imagine what someone like me can learn about using color from a guy who paints realistic art for a living?
And so it went, the house painter, muralist and plasterer. Three different skills coming together as one, to create something a little out of all of our comfort zones.
There are a number of highly respected companies importing and selling these aged lime plaster materials, and most offer some form of training opportunity ranging from a one day introductory course to an advanced week long session like the one I describe above. Many apprenticeship programs are now incorporating this type of training into their curricula for both apprentices and journeyman upgrading. If you feel the need to broaden your skills and knowledge of the trade, I highly recommend taking advantage of the opportunity that best suits your situation.
I am hopeful that someone will soon be able replicate the manufacturing process used in Italy and we can utilize domestic lime for these products. Aside from helping our own economy, it would add to the LEED credits by lowering the overall cost of transporting the material to the job site. If anyone is familiar with a domestically mined and manufactured aged-lime product designed for this use, please let me know! W&C