Plastered walls are not ideal for fireplaces. They could be for a good and decent choice for indoor (and even outdoor) walls and floors, but never for your fireplace.
When you build your fireplace with plastered wall, you have to finish it with some kind of paint – which is a highly flammable element. And that will never be safe for your home (https://www.pipefiks.no/). Additionally, from design point of view, you cannot leave the fireplace unpainted. You will need to paint it to give it some charm and attraction of its own.
A large number of people build fireplace not only for keeping their home warm, but also to enhance the look of their indoor spaces. Fireplaces are often built to work as the center or focus of interior design.
Natural stones like slate, granite, etc. can be used to build fireplace in your home. (https://pipefiks.no/piperehabilitering/) The biggest advantage of using these stones is, they are naturally beautiful. Plus, they are strong and durable. Here are some of the biggest advantages of using natural stone tiles for building fireplace –

Heat Tolerance –
Natural stones can tolerate high temperature that a fireplace. In fact, they can be used in any fireplace, no matter if you have a wood-burning, gas-burning, and electric fireplace (https://www.pipefiks.no/tjenester/staalpiper). They do not crack or get damaged because of heat. Plus, they never catch fire, like some cheap grade ceramic tiles.
Simple Cleaning –
Even though cleaning fireplace sounds like a tiring routine, it is quite simple and quick. However, you will need to seal and protect your stone against stains and that infamous layer of carbon fireplaces are known for.
If you seal and treat your stone fireplace correctly, it will be a lot easier for you to clean it.
Increased Home Value –
Another great advantage of building natural stone fireplace is that, it increases the monetary value of your home. Natural stones are beautiful and strong, and they give your fireplace a unique look with their naturally occurring colors, shades, textures, and veining and swirling patterns.