Click here to go back to frontpage -

Clay construction and radioactivity – radiation exposure and absolute dating

Clay earth is considered a durable and sustainable building material, as demonstrated by the thousands of preserved clay earth houses in central Germany.

  • Runtime: 05/2023 bis 04/2025
  • Supporter: BMBF with the program line "WIR! – Wandel durch Innovation in der Region“
  • Partner: Landesamt für Denkmalpflege und Archäologie Sachsen-Anhalt

Clay earth is considered a durable and sustainable building material, as demonstrated by the thousands of preserved clay earth houses in central Germany. Clay earth has many positive natural properties: it is mouldable, fire-resistant, open to diffusion, sound-insulating, recyclable, moisture-regulating, heat- and cold-regulating, repairable and is a raw material that is available almost everywhere.

The central innovation paths in earth building of the We! alliance GOLEHM are:

  • The certification of earth as a building material in terms of sustainability, CO2 footprint, safety and healthy living
  • Knowledge transfer with educational and information programmes to achieve regional acceptance
  • The recording, preservation and further development of the existing building stock
  • The development of modules and automated application for new buildings

As part of our project led by Prof Dr Ernst Pernicka, we are making two key contributions to the innovation paths outlined for the GOLEHM initiative.

Like any mineral building material, clay contains radioactive components that can escape into the air. The intensity of the outgassing (exhalation) of the strong alpha emitters thoron and radon is made possible by the porosity and permeability of the building material; diffusion and thermal convection are the most important control variables. Therefore, the meteorological variables, air pressure, temperature, wind strength and exposure, as well as the room temperature must be measured if the concentration of the radiating gases in a building is to be assessed. The radiation exposure and its control variables must therefore first be comprehensively recorded using various measurement set-ups in order to be able to assess the health risks of living in solid earth buildings and, if the radiation exposure is above the guideline values, to formulate recommendations for reducing it.

At the end of the project, instructions will be developed on how to minimise radon and thoron gassing from loams in order to help activate loam construction in the WIR! region.

At the same time, radioactive decay products offer the possibility of absolute dating of solid earth building components. For existing buildings within the WIR! region, a typochronology of different construction methods and forms in solid earth building can thus be developed for the first time, which will also revolutionise building research into the late Middle Ages and early modern period outside the WIR! region.

Further information: www.golehm.de