Asbestos Siding Shingles — United States Gypsum Company

Product Description

United States Gypsum Company (USG) manufactured asbestos-containing siding shingles from approximately 1937 through 1975. These flat or textured fiber-cement panels were designed as exterior cladding for residential and commercial buildings, offering a durable, weather-resistant alternative to traditional wood siding. During the mid-twentieth century, asbestos-reinforced siding shingles represented a widely adopted building material, marketed for their fire resistance, dimensional stability, and relatively low maintenance requirements.

USG was one of the country’s largest building materials manufacturers during this era, and its siding shingle product line was distributed broadly across the United States. Builders, contractors, and homeowners selected these panels as a practical and cost-effective cladding solution for new construction and renovation projects alike. The shingles were typically installed in overlapping rows along exterior walls, nailed directly to sheathing or furring strips, in a manner closely resembling traditional wood shingle installation.

Production of these asbestos-containing siding shingles continued for nearly four decades, meaning that buildings constructed or re-sided at any point between the late 1930s and the mid-1970s may still contain this material. Many structures across the country retain the original shingles, which remain a concern for renovation workers, demolition crews, and inspectors operating in older building stock today.

Asbestos Content

USG’s siding shingles incorporated chrysotile asbestos — the most commonly used asbestos fiber type in North American building products throughout the twentieth century. Chrysotile, sometimes called “white asbestos,” is a serpentine mineral fiber that was valued by manufacturers for its tensile strength, flexibility, and resistance to heat and chemical degradation.

In fiber-cement siding products of this type, chrysotile asbestos was combined with Portland cement and other binding agents, then pressed into sheet or shingle form. The asbestos fibers served as reinforcement within the cement matrix, providing structural integrity and preventing cracking under thermal expansion, impact, and weathering stress. The resulting composite material was dense and hard when undisturbed.

Although chrysotile is sometimes characterized as less hazardous than amphibole asbestos varieties such as crocidolite or amosite, regulatory and scientific consensus — reflected in OSHA standards, AHERA guidelines, and the findings of numerous occupational health studies — establishes that chrysotile asbestos is a recognized human carcinogen at occupational exposure levels. No safe threshold of asbestos fiber inhalation has been established by U.S. regulatory authorities.

Under AHERA (the Asbestos Hazard Emergency Response Act) and applicable OSHA construction standards, fiber-cement building products containing asbestos are classified as regulated asbestos-containing materials (ACM) that require specific handling, abatement, and disposal procedures.

How Workers Were Exposed

Asbestos exposure associated with USG siding shingles was primarily occupational in nature, affecting industrial workers generally and the broader range of tradespeople who manufactured, handled, installed, cut, or removed these products over the course of their working lives.

During Manufacturing: Workers employed at facilities producing asbestos-cement siding shingles faced some of the most significant potential exposure. Mixing raw chrysotile fiber with cement, forming and pressing sheet material, trimming finished shingles, and cleaning production equipment all created opportunities for airborne fiber release in an era when industrial ventilation controls and respiratory protection were often inadequate or absent entirely. Dust accumulation on clothing, machinery, and surfaces in manufacturing environments could result in prolonged and repeated exposure.

During Installation: Construction laborers and carpenters who cut, scored, snapped, and drilled asbestos siding shingles on job sites released chrysotile fibers into the surrounding air. Cutting with hand saws, circular saws, or scoring tools — common methods for fitting shingles around windows, doors, and corners — was particularly likely to generate respirable dust. Workers in close proximity to cutting operations, as well as those working in enclosed or poorly ventilated spaces, faced elevated exposure risks.

During Repair and Renovation: Maintenance workers and renovation contractors who broke, drilled, or sanded existing asbestos siding shingles disturbed the fiber-cement matrix and released previously bound chrysotile fibers. Older shingles that had weathered, cracked, or deteriorated were especially friable and prone to releasing fibers with minimal mechanical disturbance.

During Demolition and Removal: Demolition workers tasked with removing siding from structures built between 1937 and 1975 faced exposure risks from breaking and handling aged asbestos shingles. Before regulatory frameworks and modern abatement practices were established, such work was frequently performed without respiratory protection or engineering controls.

In all of these settings, workers in adjacent trades — painters, electricians, plumbers, and laborers working in proximity to siding operations — could also be exposed through bystander or secondary inhalation of airborne fibers.

Documented Trust Fund / Legal Options

United States Gypsum Company has been a defendant in asbestos personal injury litigation, and litigation records document claims brought by workers who alleged asbestos-related injuries arising from exposure to USG asbestos-containing products, including siding shingles. Plaintiffs alleged that USG manufactured and distributed asbestos siding products during a period when the company knew or should have known of the health hazards associated with chrysotile asbestos fiber inhalation, and that adequate warnings were not provided to workers or consumers.

No dedicated USG asbestos bankruptcy trust fund has been established for this product line, which means that claims against United States Gypsum for siding shingle-related asbestos exposure are pursued through direct civil litigation rather than through a pre-established trust fund claims process.

Individuals who believe they were exposed to asbestos from USG siding shingles and who have received a diagnosis of an asbestos-related disease — including mesothelioma, asbestos-related lung cancer, asbestosis, or pleural disease — may have legal options that include:

• Direct litigation against responsible manufacturers, distributors, or premises owners
• Claims against other manufacturers’ asbestos bankruptcy trusts if exposure involved multiple asbestos-containing products from companies that have established trusts
• Veterans’ benefits claims where applicable, if asbestos exposure occurred during military service involving construction or shipbuilding activities

Because asbestos-related diseases typically have latency periods of 20 to 50 years between initial exposure and clinical diagnosis, workers exposed to USG siding shingles during the 1937–1975 production period may only now be receiving diagnoses. Statutes of limitations for asbestos claims vary by state and generally begin running from the date of diagnosis or the date a claimant reasonably should have connected their illness to asbestos exposure.

Individuals seeking to understand their legal options should consult with an attorney experienced in asbestos litigation, who can evaluate the specific exposure history, applicable jurisdictions, and available defendants or trust funds relevant to each case.

This article is provided for informational and reference purposes only. It does not constitute legal advice. Individuals with potential asbestos-related claims should seek qualified legal counsel.