G.B. Corrugated “400” Siding and Roofing Material

Product Description

G.B. Corrugated “400” Siding and Roofing Material was a corrugated sheet product manufactured under the National Gypsum Company’s product portfolio. National Gypsum, headquartered in Dallas, Texas, was one of the largest building materials manufacturers in the United States throughout much of the twentieth century, producing a wide range of construction and industrial products sold under several brand names, including the “G.B.” label.

Corrugated siding and roofing sheets of this type were widely used in industrial, agricultural, and commercial construction applications. Their corrugated profile provided structural rigidity with relatively thin material, making them practical for large-span roofing systems, exterior wall cladding on warehouses and manufacturing plants, and agricultural outbuildings. The “400” designation identified a specific product line or performance grade within National Gypsum’s corrugated sheet offerings. These materials were marketed as durable, weather-resistant solutions capable of withstanding harsh environmental conditions, which contributed to their appeal across a broad range of building projects throughout the mid-twentieth century.

Because corrugated fiber-cement and similar composite sheet products of this era commonly incorporated asbestos mineral fibers as a reinforcing and binding agent, the G.B. Corrugated “400” product has appeared in asbestos-related litigation involving National Gypsum and affiliated entities.

Asbestos Content

Corrugated sheet products manufactured during the period when National Gypsum produced the G.B. product line were consistent with industry-wide practice of incorporating asbestos fibers into cement and composite matrices. Chrysotile asbestos — the most commercially prevalent form of the mineral — was routinely used in fiber-cement corrugated products as a reinforcing agent, improving tensile strength, fire resistance, and dimensional stability in the finished sheet.

Litigation records document that plaintiffs alleged the G.B. Corrugated “400” Siding and Roofing Material contained asbestos fibers as a component of its manufacturing composition. The addition of asbestos to corrugated sheet materials was a standard and widely documented practice among building products manufacturers of the period, and regulatory and industrial hygiene records from the twentieth century confirm that such products could release respirable asbestos fibers when cut, drilled, broken, or otherwise mechanically disturbed.

While the precise asbestos content percentage for the G.B. Corrugated “400” is not independently documented in publicly available product specifications, fiber-cement corrugated products of similar construction and era have been identified in asbestos hazard assessments conducted under the Asbestos Hazard Emergency Response Act (AHERA) and related regulatory frameworks as materials capable of releasing asbestos fibers under friable or damaged conditions.

How Workers Were Exposed

Exposure to asbestos fibers from corrugated siding and roofing products occurred primarily during fabrication, installation, maintenance, and removal activities. The corrugated sheet form required on-site cutting and shaping to fit structural dimensions, and these operations — performed with hand saws, power circular saws, and angle grinders — generated dust that litigation records document as a source of asbestos fiber release.

Industrial workers generally represent the trade category most closely associated with documented exposure to the G.B. Corrugated “400” product. Workers employed in manufacturing plants, industrial facilities, refineries, power generation stations, and similar heavy-use environments frequently worked in or near structures clad or roofed with corrugated asbestos-containing sheet materials. Maintenance crews tasked with repairing damaged roofing panels, replacing deteriorated sections, or working overhead in buildings where these materials were installed were at particular risk of inhaling airborne asbestos fibers released during disturbance of the material.

Plaintiffs alleged that cutting and fastening corrugated sheets during original installation generated significant dust exposure for roofing and siding mechanics, carpenters, and laborers working on industrial construction projects. Maintenance workers who drilled fastener holes, broke panels during repair, or swept debris from deteriorating corrugated roofing also alleged occupational exposures through these activities.

Secondary exposure was documented in litigation records involving bystander workers — those employed in adjacent trades or areas who were present when corrugated sheet work was performed but who were not directly handling the material themselves. In large industrial construction environments, bystander exposures represented a recognized pathway given that asbestos-fiber-containing dust could travel considerable distances from active cutting or demolition work.

Deterioration over time also posed a continuing exposure risk. Corrugated roofing and siding materials installed on structures were subject to weathering, impact damage, and mechanical degradation, conditions that could render previously stable asbestos-containing material friable and capable of releasing fibers into occupied work environments. Maintenance personnel, inspectors, and workers stationed inside facilities with aging corrugated roofing have appeared in litigation records as claimants alleging chronic low-level exposures from deteriorating overhead materials.

OSHA’s permissible exposure limits and action levels for asbestos, established and periodically revised in regulations codified at 29 C.F.R. § 1910.1001 and § 1926.1101, reflect the regulatory determination that occupational asbestos exposure presents serious health risks including mesothelioma, asbestosis, and lung cancer — diseases alleged by plaintiffs in litigation involving National Gypsum products.

Legal Tier: Tier 2 — Litigated Product

The G.B. Corrugated “400” Siding and Roofing Material is documented as a Tier 2 product, meaning that legal claims associated with this material have proceeded through civil asbestos litigation rather than through a dedicated asbestos bankruptcy trust fund established by a former manufacturer.

National Gypsum Company did file for Chapter 11 bankruptcy protection, and an asbestos settlement trust — the National Gypsum Settlement Trust — was established through that reorganization to address certain asbestos-related claims. However, claimants whose injuries are specifically associated with the G.B. Corrugated “400” product should consult qualified asbestos litigation counsel to evaluate whether their particular exposure and disease circumstances align with the categories of claims covered under the trust’s claims procedures, or whether civil litigation against solvent successor or related entities represents the appropriate legal avenue.

Litigation records document that plaintiffs have alleged injuries including mesothelioma, lung cancer, and asbestosis in connection with exposure to National Gypsum-manufactured products. Claims involving corrugated sheet materials have been included among the product-specific allegations brought against National Gypsum and related defendants in asbestos personal injury proceedings.

Individuals who worked in industrial environments where the G.B. Corrugated “400” product was installed, maintained, or removed, and who have subsequently been diagnosed with an asbestos-related disease, are encouraged to seek legal counsel experienced in asbestos product identification and multi-defendant litigation. Documenting the specific product, work site, employer, and time period of exposure is essential to supporting a legal claim, and attorneys specializing in this area can assist in identifying all potentially responsible parties and applicable legal remedies.

This article is provided for informational reference purposes only and does not constitute legal advice. Individuals with potential asbestos-related claims should consult a licensed attorney.