Tallinn University of Technology

Instead of painting your walls and pasting wallpaper over them, TalTech researchers recommend using traditional finishing materials, which have the benefits of being natural, having a smaller environmental footprint, being recyclable, and often even creating a more pleasant indoor climate, Postimees reports.

loodussõbralikud viimistlusmaterjalid lubi savi
Photo: Pixabay

Author: Kristina Traks

Examples of such finishing materials include clay, lime, hempcrete, and paper plaster. Estonians have used clay as a building material for centuries. The properties of clay have also been studied at Tallinn University of Technology for many years. Aime Ruus, associate professor of the Building Materials and Physics curriculum at Tartu College of the School of Engineering of TalTech, says that the idea to study the moisture properties of clay plaster came from Saviukumaja, a company that manufactures and sells clay plasters in Southern Estonia. ‘The composition of clay varies a lot depending on the region it comes from,’ says Ruus. ‘Our experiments showed that the water vapour binding capacity of clays of different origins differed by a factor of up to twenty.’

The potential uses of clay plaster today are vast. It comes in all shades, and interest in this finish is constantly growing, according to Ruus. Not only in Estonia, but also in foreign markets: Saviukumaja operates internationally and has also been to the Middle East, for example, to apply clay plaster to walls. ‘In a way, using clay plaster is a well-being issue – on the one hand, it creates an indoor climate that makes the room feel really good to be in, but on the other hand, it makes you feel good to know that you are using a truly natural, traditional, and recyclable material,’ says Ruus.

Lime – a valuable building material

Another natural and traditional material is lime plaster, which has historically been used in Estonia for interior and exterior finishing. Lime is a valuable building material that has been used, for example, to build the Old Town of Tallinn, where most of the buildings are rendered with lime mortar. Interior surfaces finished with lime plaster ensure a more stable humidity level in the rooms. Lime-treated surfaces are anti-static and the fire resistance of the structures is improved. ‘The issue of carbonation is an interesting one for lime plaster. It is fundamentally a very different material from clay – for example, its environmental footprint is different simply because lime requires burning prior to use. However, when applied to walls, lime binds carbon,’ Ruus explains. Lime mortar can be used in farmhouses, city apartments, and outbuildings alike. Plaster can be applied to a variety of surfaces and lime is also suitable for damp rooms such as basements.

Read more about what hempcrete and paper plaster are as finishing materials in Postimees.