USG Cover Coat / Sheetrock Smoothcoat / Perf-A-Tape System

Product Description

United States Gypsum Company (USG), one of the dominant manufacturers of wallboard and finishing products throughout the twentieth century, produced a line of interior finishing compounds under several related trade names, including Cover Coat, Sheetrock Smoothcoat, and the Perf-A-Tape System. These products were marketed as complete finishing solutions for gypsum wallboard installations, designed to conceal seams, cover fasteners, and deliver smooth, paint-ready wall surfaces in both residential and commercial construction.

The Cover Coat and Smoothcoat compounds were applied in multiple coats over taped wallboard joints, with each successive layer feathered outward to blend seamlessly with the surrounding surface. The Perf-A-Tape System incorporated perforated paper joint tape used in conjunction with the finishing compound, intended to reduce bubbling and improve adhesion across seams. Together, these products were widely specified by contractors, drywall finishers, and building trades workers from approximately 1950 through 1977, a period during which asbestos was commonly incorporated into joint compound formulations to improve workability, reduce cracking, and enhance the texture of finished surfaces.

USG was a major supplier to the construction industry throughout this era, and its products appeared in commercial office buildings, schools, hospitals, apartment complexes, and single-family homes across the United States. The widespread distribution and long service life of these compounds means that materials applied during this period may still be present in structures that have not undergone asbestos abatement.

Asbestos Content

Litigation records document that USG’s Cover Coat compound, Sheetrock Smoothcoat, and related Perf-A-Tape finishing products contained chrysotile asbestos during the period of approximately 1950 to 1977. Chrysotile, also known as white asbestos, is a serpentine-form fiber that was widely used in building products throughout the mid-twentieth century due to its flexibility, tensile strength, and resistance to cracking under stress.

In joint compound formulations, chrysotile asbestos served as a functional additive. It helped bind the compound, improved its spreadability during application, and reduced the tendency of dried compound to shrink or crack — qualities that made it attractive to manufacturers competing in the construction products market. Plaintiffs alleged that USG incorporated chrysotile asbestos into these finishing compounds as a deliberate product design choice and continued to do so for decades despite growing awareness within the industry of asbestos-related health hazards.

The U.S. Environmental Protection Agency’s Asbestos Hazard Emergency Response Act (AHERA) and subsequent regulatory frameworks have established that chrysotile asbestos fibers, when disturbed, can become airborne and lodge in lung tissue, where they may cause asbestosis, pleural disease, lung cancer, and malignant mesothelioma — a rare and aggressive cancer of the lining of the lungs, abdomen, or heart. Mesothelioma carries a latency period of 20 to 50 years, meaning workers exposed to these products during the 1950s through 1970s may only now be receiving diagnoses.

How Workers Were Exposed

Workers who applied, sanded, and otherwise disturbed USG Cover Coat, Sheetrock Smoothcoat, and Perf-A-Tape compound during their working years faced potential inhalation exposure to airborne chrysotile asbestos fibers. Litigation records document that the finishing process for gypsum wallboard was particularly hazardous because it involved multiple phases of work that could generate fine airborne dust.

During application, finishers mixed dry compound with water or used pre-mixed formulations, spreading the compound over joints with broad knives and trowels. Dry compound mixing was documented as generating significant dust. During drying and sanding, workers used pole sanders, hand sanders, and sanding blocks to smooth each coat before the next was applied — a process that abraded the dried compound and released fine particles, including asbestos fibers, directly into the breathing zone.

Industrial workers generally who worked in construction environments where these products were in use — including drywall finishers, tapers, plasterers, general laborers, and building tradespeople — were documented as potentially exposed. Bystander exposure was also a recognized concern, as airborne fibers generated during sanding could travel through open floor plans, elevator shafts, and HVAC systems to affect other trades working in the same area.

Plaintiffs alleged that USG was aware, or should have been aware, that its joint compound products released asbestos fibers during normal and foreseeable use, and that the company failed to adequately warn workers of the associated health risks. Prior to OSHA’s asbestos standards taking effect in the early 1970s, workers in many settings had no regulatory protection, no required respiratory equipment, and no warning labels directing them to take precautions during sanding or mixing operations.

Workers performing renovation and demolition in buildings where these products were installed remain at risk today. Disturbing old joint compound during remodeling — by cutting, grinding, sanding, or demolishing drywall — can release preserved asbestos fibers from products applied decades earlier.