Venetian Plaster Guide: Definition, Installation, Uses & More

A fairly modern term, Venetian plaster refers to the ancient method of plastering walls by applying a stuccoed coating. Dating back to the Ancient Greeks and Egyptians, Venetian plaster was used to improve the wall’s physical endurance, whilst also creating an earthy, smooth appearance.

Venetian Plaster: What Makes This Type Of Plaster Unique?

Venetian plaster is a term that refers to a limestone-based putty that is used to plaster walls. Also referred to as lime plaster, this mixture is created by mixing fired limestone with water. When this mixture is applied to a wall, it is exposed to the air’s natural carbon dioxide as it dries. This process has an incredible effect on the Venetian plaster mix, as the addition of these chemical elements turns the plaster back into limestone.

What sets this type of plaster apart from others, is that Venetian plaster does not contain any aggregates. For example, gypsum plaster and earthen plaster include marble, glass or granite within their mixture, in an attempt to increase their strength and durability. However, with Venetian plaster, there are no aggregates. This results in a high-end, polished marble effect that is suitable for plastering walls, floors and ceilings.

How Do You Make Venetian Plaster?

To mix up a batch of lime putty to create Venetian plaster, you must first measure out some fired limestone. For the most successful plaster mix, a limestone of pure calcium carbonate should be selected. The rock must then be limekiln-fired at temperatures around 1000°C to create a substance known as quicklime. Quick lime is an extremely corrosive material consisting of calcium oxide, making it a very difficult material to store.

Once you have your quick lime, you must immediately add enough water content to create calcium hydroxide or, as it is more commonly known, lime putty. A process known as ‘slacking’ follows, due to the chemical reactions that take place a lot of heat and steam are released throughout this process.

What is produced is lime putty; this mixture can be applied and manipulated to create both smooth and decorative finishes. The Venetian plaster mix will dry and harden slowly, giving a plasterer ample time to create the intended aesthetic.

The Characteristics of Venetian Plaster

Purely on its appearance, Venetian plaster is renowned for its iridescent finish, especially when a skilled plasterer applies multiple layers of the thin, translucent mixture. The shimmer when it dries creates a luxurious finish that is enhanced when it is dappled by natural light.

Pigments, both synthetic and natural, can be added to the lime putty creating shades of whites, greys and beiges, as well as browns and blacks. With such a range of colours and tones, Venetian plaster allows for a soft, earthy feeling to come through.

Other characteristics of Venetian plaster lie in its composition. The limestone-based plaster is extremely sanitary, allowing for any moisture to escape from the internal layers. And, consequently, this helps Venetian plaster to be mildew and mould-resistant. In addition, with only natural materials, this type of plaster is also non-toxic, emitting no VOCs (volatile organic compounds).

How Is Venetian Plaster Applied To A Surface?

The most effective Venetian plaster surfaces are achieved by a skilled plasterer using a selection of unique tools. There are cheaper, modern variations for those brave enough to do it themselves; however, with Venetian plaster, an element of ‘you get what you pay for’ does ring true. The higher the quality of Venetian plaster and the more experienced the plasterer, the better the finish will be.

Most plasterers opt for a particular spatula or trowel to administer Venetian plaster mix. The lime putty is then applied thinly, in somewhat loose layers. The process is repeated often three times to build up a few layers of plaster. Using this technique, the swirls add depth to the surface and, once waxed and polished, produce an impressive finish.

Applying Venetian Plaster: A Step-By-Step Guide

For those intrigued about how this plaster finish is achieved, our basic step-by-step guide will provide you with an adequate understanding of this aggregate-free plastering technique. The best advice is to practice your technique on some drywall sheets before jumping in on the main feature wall or ceiling.

1. Prepare Your Room/Area

Whilst it may seem obvious, it is important to make sure all the preparation for your room and working area have been completed before you mix up your lime plaster. Use dust sheets to cover any furniture that cannot be removed and cover the floor.

If your wall or ceiling has any defects such as small cracks or holes, these must be filled and sanded down before you get started. Remove any dust, dust and grease from the entire area, before priming with flat paint.

2. Begin Your First Coat Of Plaster

Create your lime putty, being sure to measure and record the amount of pigment you add – again, it is advisable to test out the colour before a sheet of drywall. Once the plaster is the right consistency, it is time to start your application.

Begin in a corner, and work across the wall. Using a 4-6 inch drywall knife or flexible steel troll, hold your instrument at a 15-30 degree angle to the wall and apply a thin coat of plaster. Use a variety of strokes, both in length and angle, to apply the putty. You are aiming for reasonably smooth coverage.

Clean your trowel or drywall knife and allow the first coat to completely dry, before starting the second. The drying process should take approximately four hours.

3. Applying The Second Coat

For your second coat of plaster, there is a slightly different technique to adopt. This time, hold the same utensil at a 60-90 degree angle to apply another thin layer. Use an X-shaped stroke to thoroughly cover the wall, filling in any areas that were missed and remove any high spots.

For this layer, allow it to dry for a good 24 hours before moving on to the next step.

4. Time To Burnish

Venetian plaster must be burnished once it has dried. This involves using very fine sandpaper, between 400-600, to rub down the plaster in circular motions. If you are looking to achieve a highly polished finish, the surface can then be wiped down and the process can be repeated with the flat side of your trowel or drywall knife.

5. Do You Need A Topcoat?

With Venetian plaster, a topcoat is optional. However, if you are applying this type of plaster to a bathroom or a room that experiences high traffic, it is recommended to use a suitable topcoat. These are often applied with a trowel as soon as the plaster has dried for 24 hours.

It is worth noting that a topcoat will darken the colour of your Venetian plaster, so do consider this before you add in your pigments.

Once a topcoat has or has not been added, you can now apply a thin coat of wax and repeat the burnishing process. A wax coating will help protect the plaster while creating a gloss sheen.

The Benefits Of Venetian Plaster

In its most authentic form, this type of plaster is an extremely environmentally-friendly choice as it uses natural materials with no additional aggregates. For builders and renovators looking to create a natural finish that does not compromise on quality, Venetian plaster is a popular choice.

Similarly, it is extremely adaptable to a wide variety of interiors due to the expansive range of colours and textures that can be created. Both textured and smooth finishes can be achieved by professional tradesmen. This allows for a biophilic design where the external world is celebrated and brought inside. Venetian plaster allows this to be implemented through earthen textures or a seamless vision.

An additional advantage is how low maintenance it is within a lived-in home. The plaster itself is extremely durable; but, if a blemish was to occur in the future, repairs are possible.

Specialist Plastering Services

To ensure your vision is executed to the highest of standards, it is recommended to seek a professional’s services. This quality finish benefits from an expert’s knowledge and handling, allowing your property to display the application for years to come.

At AB Drylining, we can help advise you on which type of plaster is most suitable for your property and interior design. Get in touch with our specialist plasterers today to benefit from our expert eye and years of experience. We can also offer professional plastering services to commercial clients and have been CSCS certified, as well as PASMA and IPAF accredited.