Asbestos Cement Roofing Shingles — GAF Corporation

Product Description

Asbestos cement roofing shingles were among the most widely manufactured and installed roofing materials in the United States from the 1930s through the late 1970s. GAF Corporation, one of the country’s largest building materials manufacturers during this period, produced asbestos cement roofing shingles as a core product line marketed extensively to residential, commercial, and industrial construction markets.

These shingles were engineered as a composite material combining Portland cement with asbestos fibers, pressed and cured into rigid, flat or contoured panels designed to mimic the appearance of traditional slate or wood shingles. The finished product was promoted for its fire resistance, weather durability, and dimensional stability — properties that made it attractive for decades of use across nearly every segment of the construction industry.

GAF Corporation operated through several corporate predecessors and subsidiaries, including General Aniline & Film Corporation and related entities, and maintained manufacturing facilities that produced asbestos-containing building products throughout this era. The company’s roofing shingles were distributed through building supply chains, wholesale distributors, and contractors nationwide, placing them in an enormous number of structures that remain standing today.

Production of asbestos cement roofing shingles by GAF and other manufacturers effectively ended following the increased regulatory scrutiny of the 1970s, including actions by the Environmental Protection Agency (EPA) and the framework later codified under the Asbestos Hazard Emergency Response Act (AHERA) of 1986, which established standards for identifying and managing asbestos-containing materials in buildings.

Asbestos Content

Asbestos cement roofing shingles manufactured by GAF Corporation contained asbestos fiber as a primary structural component. Chrysotile asbestos — the most commercially prevalent fiber type — was the predominant variety used in cement-bonded roofing products of this type, though documentation from this manufacturing period also reflects the use of amphibole fibers, including amosite, in certain formulations and production runs.

In asbestos cement products, asbestos fibers were blended into a slurry with Portland cement and water, then formed under pressure into sheet or shingle form and allowed to cure. The resulting material typically contained asbestos fiber by weight at concentrations that regulatory and occupational health literature has consistently identified as hazardous when the material is disturbed, cut, broken, or abraded.

AHERA and OSHA standards classify asbestos cement roofing materials as a regulated asbestos-containing material (RACM) when friable or when subject to disturbance during installation, maintenance, repair, or removal. Under OSHA’s asbestos standards (29 CFR 1910.1001 and 29 CFR 1926.1101), work involving asbestos cement roofing products is subject to permissible exposure limits, required engineering controls, and mandatory respiratory protection protocols — a regulatory framework that reflects the documented fiber-release potential of these materials.

How Workers Were Exposed

Industrial workers and construction trades personnel were exposed to asbestos fibers released from GAF Corporation asbestos cement roofing shingles at multiple points across the product lifecycle.

Manufacturing workers at GAF facilities were exposed during the mixing, pressing, cutting, and finishing of asbestos cement shingle stock. Dry asbestos fiber handling and the mechanical processing of uncured and cured cement board generated airborne fiber concentrations in production environments.

Roofers and installation crews encountered fiber release whenever shingles were cut to fit, drilled for fasteners, or broken during handling on the job site. The use of hand saws, power saws, and other cutting tools on asbestos cement shingles generated fine dust containing respirable asbestos fibers. Workers who installed these products without respiratory protection — which was common practice through much of the production period — accumulated significant occupational exposures.

Maintenance and repair workers disturbed previously installed asbestos cement roofing shingles during re-roofing projects, patching operations, and building renovation work. Aged and weathered shingles that had become brittle were particularly prone to fracture and fiber release when handled.

Demolition workers removing structures containing GAF asbestos cement roofing shingles were exposed to high-concentration fiber release, particularly in the absence of wet-method controls or appropriate personal protective equipment.

General laborers and bystanders working in proximity to any of the above activities were also subject to secondary fiber exposure from airborne dust generated at roofing job sites and manufacturing facilities.

The latency period between asbestos exposure and the development of asbestos-related disease — including mesothelioma, asbestosis, lung cancer, and pleural disease — typically spans decades, meaning that workers exposed to GAF roofing shingles during the product’s manufacturing and installation peak may be receiving diagnoses today.