Demotorstai: More Than Mud - The Hidden Benefits of Clay Plaster

Could a low-carbon, reusable building material improve indoor comfort? How does clay perform when it comes to moisture regulation, fire safety and indoor air quality? And what potential does Finland's abundant clay resource hold for future construction? Clay is one of the oldest building materials in the world, yet it is attracting renewed interest as a low-carbon, reusable and locally available resource. Clay plasters can be made from naturally occurring Finnish clays, including surplus soil from excavation sites. They are valued for their ability to regulate indoor humidity, contribute to thermal comfort, and act as a natural fire retardant. Because clay is unfired and contains no chemically binding substances, it can be reused simply by mixing it with water again. In this Demotorstai webinar, we will explore the findings of a newly published report on Finnish clay plasters. The study examines their moisture buffering capacity, mould susceptibility, microbiological characteristics and ability to adsorb volatile organic compounds (VOCs). The results offer valuable insights into how clay-based materials perform in real indoor conditions and their potential to support healthy, comfortable and low-carbon buildings.