Characterization of Biodegradation of Fiber Cement Shingles by Scytonema Sp. Using Optical and Scanning Electron Microscopy

Fiber cement roofing shingles from condominiums in Hawaii were examined for deterioration using optical and scanning electron microscopy. The product has a 50 year warranty and had been in service since 1994. Shingle samples were taken in August and September, 2000 after a growing volume of reports...

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Bibliographic Details
Published in:Microscopy and Microanalysis
Main Authors: Reine, Barbara A., Murphy, Colin
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press (CUP) 2001
Subjects:
Online Access:http://dx.doi.org/10.1017/s1431927600028439
https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S1431927600028439
Description
Summary:Fiber cement roofing shingles from condominiums in Hawaii were examined for deterioration using optical and scanning electron microscopy. The product has a 50 year warranty and had been in service since 1994. Shingle samples were taken in August and September, 2000 after a growing volume of reports of roofing deterioration were received by the condominium association. Close-up visual inspection confirmed that the roof areas showing deterioration were covered with a black growth. Roofing samples from areas exhibiting deterioration, areas with no deterioration, and new material were compared by microscopy. Examination of the black growth by optical microscopy revealed it to be primarily the Cyanobacterium, Scytonema sp. This is a filamentous organism found from the Arctic to the Antarctic, and is common to Oahu and Maui.’ Other organisms observed to be present are Chroococus sp., Gloeocapsa sp., Aphanocapsa sp., Oscillatoria sp., a very few Trebouxia sp. and lichens.