Wirksamkeit und Dauerhaftigkeit von Bioziden in Bautenbeschichtungen

Abstract

The use of external thermal insulation systems (ETICs) is a powerful instrument in the energetic improvement of residential buildings. With that measure, the façade surface is thermally decoupled from the wall construction and consequently the humidity balance on the façade changes. This fact leads to better conditions for the growth of microorganisms. Therefore biocidal ingredients are often added to façade coatings. To evaluate the effectiveness and the durability of biocidal equipped façade coatings a comprehensive research project was conducted at the Holzkirchen branch of the Fraunhofer-Institute for Building Physics. 33 different types of façade coatings were applied to test specimen and exposed to real weathering conditions for five years. The general efficiency of the biocidal equipping of façade coatings could be proven. The development of biological growth on biocidal equipped façade coatings was significantly reduced, showing much less species than without biocide. Depending on the type of the coating, different biocides show a varying durability within the coatings. This has an influence on the species involved in the primary colonization. The biocide content in the coating itself allows no prediction of the susceptibility to biological growth. Façade coatings with biocidal paints showed better results than biocidal renders without additional paint coating

Biocide emissions from building materials during wet weather: identification of substances, mechanism of release and transfer to the aquatic environment

“…hydrolysis, biodegradation, direct and indirect photolysis (Fenner et al 2013) and, in most cases, transformation products (TPs) are formed as a result of incomplete degradation (Hensen et al 2018). TPs of some biocides are directly formed in the material itself by photodegradation, which is the most common degradation process (Burkhardt et al 2012;Breuer et al 2012;Luo et al 2013;Bollmann et al 2016Bollmann et al , 2017bHensen et al 2018). Identified photodegradation products are reported in table 3.…”

Using Environmental Simulations to Test the Release of Hazardous Substances from Polymer-Based Products: Are Realism and Pragmatism Mutually Exclusive Objectives?

“…Studies of coatings were performed under laboratory conditions in either simple immersion tests [94,95] or weathering chambers [93,96], in field experiments [39,[97][98][99][100], and in settlement areas [93,101,102]. Most of the studies were performed on coatings containing polymeric organic binders, but some studies also included mineral products [103].…”

Construction Process Technical Impact Factors on Degradation of the External Thermal Insulation Composite System

“…The list of degradation factors was collected through a literature review. The list of shortcomings is based on descriptive instructions, recommendations, harmonized standards, set requirements [38][39][40][41][42][43], studies regarding simulations or material studies made in laboratory conditions [11][12][13][14], field research [2,3,5,7,51,[68][69][70][71][72][73][74][75][76][77][78][79][80], and books on the topic [6,9,10] . Based on these references published between 1996 and 2015, a list of identified on-site degradation factors was created.…”