Development of a model to assess the environmental properties of common plasters and mortars

Schematic representation of the three-stage model
© Fraunhofer IBP
Schematic representation of the three-stage model for evaluating the environmental properties of plasters and mortars.

Building products such as plasters and mortars are mainly used on the exterior of buildings, where they are exposed to precipitation and the ambient air. Rainwater runoff can dissolve inorganic substances contained in them, such as heavy metals, or organic constituents like biocides and their transformation products, so that they leach into the environment. But does their release necessarily cause a problem for the environment?

Project goals

The aim of the research project is to develop a model for evaluating the environmental properties of plasters and mortars for outdoor use as part of a dissertation. For the project, or for validation purposes, an extensive data pool is available. This has been collected over a period of more than 10 years from field and laboratory experiments on a wide range of plasters and mortars used as façade building materials.

The focus is on developing a mathematical model that can be used to determine which substances might be released in relevant concentrations from plasters and mortars by rain.

The results are intended to help evaluate the environmental properties of specific building products. This will supply manufacturers with valuable information to optimize formulations and will also enable authorities to define suitable areas of application for these materials.

Current project status

A three-level model has been developed. In Level 1, the volume of rainfall runoff is calculated for a plastered façade during a fall of rain. In Level 2, the inorganic substances leaching from the building products are identified and the concentrations in which they occur determined. Lastly, in Level 3, the environmental properties of the products are evaluated. This is achieved by carrying out a so-called groundwater risk assessment.

The models can already be used to simulate the potential environmental impact of mineral formulations. To do this, various material properties of a product and the weather data of any given location must be entered into Level 1 and then run through Level 2. Finally, in Level 3, a “compliance statement” is obtained. Based on results from previous research projects, it appears unlikely that limit values will be exceeded at the assessment site.

Project partners

  • Fraunhofer Institute for Building Physics IBP
  • Chair of Urban Water Management at the Technical University of Munich
  • Chair of Building Physics at the Technical University of Munich
  • Chair of Building Materials Science at RWTH Aachen University
  • German association for insulation systems, plaster and mortar VDMP 
  • Brillux GmbH & Co. KG
  • DAW SE
  • Baumit GmbH
  • Deutsches Lackinstitut GmbH
  • Fels Vertriebs und Service GmbH & Co. KG
  • HECK Wall Systems GmbH
  • IMCD Deutschland GmbH & Co. KG
  • Knauf Gips KG
  • Sievert Baustoffe GmbH & Co. KG
  • Saint-Gobain Weber GmbH
  • Sto SE & Co. KGaA
  • Thor GmbH
  • Wacker Chemie AG
  • VDZ Technology GmbH