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Pro020

Biodeterioration of painted walls and its control



Title: Biodeterioration of painted walls and its control
Author(s): C. Gaylarde, P. M. Gaylarde
Paper category : conference
Book title: First International RILEM Workshop on Microbial Impact on Building Materials
Editor(s): M. Ribas Silva
Print-ISBN: None
e-ISBN: 2351580133
Publisher: RILEM Publications SARL
Publication year: 2000
Pages: 28 - 33
Total Pages: 6
Nb references: 17
Language: English


Abstract: Microorganisms, fungi, algae and cyanobacteria, produce discoloration on buildings and can cause their physicochemical deterioration. There is little literature on the problem of biodeterioration of constructional materials in Brazil. The objectives of this project were to test the efficacy of a novel biocide to control the biodeterioration produced by phototrophic microorganisms (algae and cyanobacteria) on the external surfaces of buildings in Porto Alegre, RS. The majority of phototrophs were cyanobacteria. A well-colonized wall was selected to test a copper-based biocide, applied at 10 and 100mg/m2. The gray-green discoloration on the gesso surface began to disappear after a few weeks. One year later, the surface appeared clean and remained so for six years in the case of the higher biocide concentration. After 33 months, a single cyanobacterial genus (Chlorogloeopsis), no algae and few fungi and bacteria were detected on these areas. A gray discoloration began to reappear on the area of higher concentration after 4 years and we detected 28 different phototrophs, as well as filamentous fungi and heterotrophic bacteria. On an adjacent, untreated, area of wall, 63 phototrophs, bacteria and protozoa and many filamentous fungi were detected. The paint film was peeling and deteriorated. The results show that the
biodeterioration of painted external walls can be controlled by the use of an algicidal compound.


Online publication: 2000-06-30
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2351580133.004