There are many differences between what we would refer to as ‘regular’ plaster here in the UK and Venetian plaster, from the raw components through to application, where to use and how it can be used, this post will give you all the information you need to know about these products.
Firstly, let’s start with the regular plaster, here in the UK most walls are coated in pink gypsum plaster which is produced by British Gypsum, this creates a smooth, flat finish that is reasonably resilient to cracking providing it has dried out at a natural pace.
The most common plaster used here is Thistle Multi Finish which is a ‘retarded hemihydrate’ and comes in bags of pre-mixed gypsum plaster, to which clean water is added and then applied to walls, it is easy to use once dried provides a hard durable inert surface that can be painted over, wallpapered or surface designed using a range of luxurious wall coverings.
It is pink in colour due to the aggregates used and processing, clay, and lime, drying a brownish pink, which can be a desirable finish for some people, as such many paint manufacturers are now offering this as a shade of paint, such as Farrow & Ball’s ‘setting plaster’ No 231.
This pre-mixed plaster will harden as it dries out, doing so removes most of the human error of measuring out the components incorrectly, controlling the airflow and humidity within the plastered rooms will have an impact on drying times.
Older buildings can feature traditional lime plaster, which is a whiter colour, due to the lime content, or you might even come across concrete plaster which is a grey colour, typically found in homes.
Venetian plaster is a traditional Italian plaster primarily made from slaked lime putty mixed with crushed marble, it then has coloured dyes or additives to give the desired shade and can be supplied in a very wide range of colours.
Typically, it comes in 3 main finishing options, depending on the grain size, which are:
- Fine grain
- Medium grain
- Coarse grain
The application of this plaster is more specialised, requiring more detailed training than the pink gypsum plaster and would usually be classed as more of a decorative finish, it is also much more labour-intensive and the raw materials are significantly higher in cost.
You’d expect to pay around £7 for a 25kg bag of powdered gypsum whereas a 25kg tub of Venetian plaster would be between £110-150.
Therefore it should come as no surprise that the investment to get this type of work done in your home will be a more sizeable investment.
Depending on the brand, finish desired and substrate that you plan to go over you could be looking at 4 or even 6 coats including the primer, base coat, and subsequent topcoats, adding up to a whole load more hours than the pink gypsum alternative.
Venetian plaster also a finished look, whereas typically people would opt to decorate over the misty pink hue left once multi-finish has dried, although not always, in which instance a clear varnish can be coated to help seal the surface and prevent it from getting stained or marked so easily.
Both options add a decent amount of surface hardness and resilience to your walls, however repairing the venetian plaster is much trickier and would usually result in another coat having to be applied, then polished up and sealed again.
To read more about the costs associated with Venetian plaster, check here.