Asbestos in Shingles and Other Building Materials
Shingles were only one of several asbestos-containing products using in roofing and construction prior to the 1980s. Asbestos shingles generally refers to the common, inexpensive composite shingles used for most residential roofs.
Asbestos shingles were the first asbestos building materials to be manufactured and marketed in the U.S. They were the innovation of one H.W. Johns of New York City, who started his company in 1858. At that time, fires were a common hazard in America's cities and remained so during most of the 19th and early 20th centuries because of the widespread use of oil and gas lighting as well as open fireplaces. It was not unusual for a spark from a chimney to ignite someone's roof. Asbestos shingles promised to mitigate property damage and save lives. Asbestos shingles were sold in the United States through the 1970s under brand names like “Supradur”.
Ironically, H.W. Johns himself died of asbestos disease in the 1890s while still in his fifties. It is doubtful that he or his physicians understood the cause of his fatal illness - but later management of the company he founded, which eventually became Johns-Manville, certainly did. By the 1930s, medical science had confirmed beyond all doubt that asbestos was responsible for a range of respiratory diseases.
Although "new" uses of asbestos are prohibited in the U.S., many products on store shelves imported from China and elsewhere may still contain small amounts of this substance.
Shingles Products Containing Asbestos
The following partial list of shingles products were known to contain asbestos:
|Product Name||Start Year||End Year|
|Flintkote Asbestos Cement Shingles|
|Flintkote Monticello Cement Shingles|
|Flintkote Roofing Shingles|
|GAF Ruberoid American Thatch Roofing Shingles|
|GAF Ruberoid American Thatch Shingles|
|GAF Timbertex Shingles|
|Johns Manville Cedargrain Asbestos-Cement Shingle||1907||1976|
|Johns Manville Colorblende Asbestos Shingles||1907||1976|
|Johns Manville Deepgrain Asbestos-Cement Shingles||1907||1976|
|Johns Manville Durobestos Asbestos-Cement Shingles||1907||1976|
|Johns Manville Fire-Glass Seal-0-Matic Roofing Shingles||1907||1979|
|Johns Manville Fire-King Seal-0-Matic Roofing Shingles||1907||1979|
|Johns Manville Standard Asbestos Shingles|
|National Gypsum Asbestos Cement Siding Shingles||1953||1981|
|National Gypsum Chromatone Siding Shingles||1954||1968|
|National Gypsum Dutch Lap Shingles||1954||1968|
|National Gypsum Hexagonal Shingles||1954||1965|
|National Gypsum Ranch-Style Shingles||1956||1969|
|United States Gypsum Siding Shingles||1937||1975|
Hazards Associated with Shingle Products
When initially installed, asbestos shingles posed relatively little risk of asbestos exposure, as the shingle material safely encapsulates the asbestos fibers. Over time, however, as the shingles are worn with age or damaged by weather, fire, or accident, the shingles begin to break down and the asbestos material becomes friable. Friable asbestos is delicate to the touch and individual asbestos fibers can easily break loose and enter the atmosphere in that state. Inhaled asbestos fibers can eventually lead to the development of diseases like pleural mesothelioma and other serious respiratory complications.
InspectAPedia. “Asbestos in Building Roofing Materials - How to identify asbestos-containing roofing.”(http://www.inspectapedia.com/sickhouse/asbestoslookG.htm) Retrieved 9 January 2011.