Asbestos Roofing Materials

Asbestos roofing materials encompass a range of products — including shingles, corrugated sheets, roofing felt, and tar paper — that were manufactured with asbestos fibers to provide fire resistance, weather durability, and structural strength. These products were among the most commonly installed roofing materials in the United States from the 1920s through the late 1970s, and they remain on millions of homes and commercial buildings today.¹

Asbestos roofing shingles were manufactured by embedding chrysotile asbestos fibers in a cement or asphalt matrix, then molding the material into shapes resembling natural slate, wood shakes, or flat tabs. These shingles typically contained 10–30% asbestos by weight and were prized for their exceptional longevity — many installations have lasted 50 years or more. Corrugated asbestos cement roofing sheets, used extensively on agricultural, industrial, and some residential structures, contained similar asbestos concentrations in a Portland cement base.²

Roofing felt and tar paper represent a less well-known but significant source of asbestos exposure. These underlayment products, installed beneath shingles or as standalone waterproofing layers, contained asbestos fibers blended with asphalt and organic felt. Roofers who handled, cut, and nailed through these materials were exposed to asbestos fibers during installation and tear-off operations.³

The primary health concern with asbestos roofing is fiber release during weathering, repair, or removal. While intact asbestos roofing shingles are non-friable, decades of exposure to sun, rain, wind, and freeze-thaw cycles gradually erode the protective surface matrix, exposing the embedded asbestos fibers. Fiber release accelerates when roofing materials are cut, drilled, broken, or removed during re-roofing projects. Roofers, demolition workers, and homeowners performing DIY roof repairs on older homes face the greatest exposure risk.¹

Asbestos was incorporated into several categories of roofing products:²

• Asbestos cement shingles — Rigid tiles molded to resemble slate, wood, or flat-tab shingles. Composed of Portland cement reinforced with chrysotile asbestos. Extremely durable but brittle; they crack and break when walked on or impacted
• Corrugated asbestos cement sheets — Large, wavy panels used for roofing and wall cladding on barns, warehouses, and industrial buildings. Same composition as Transite products
• Asbestos roofing felt — Asphalt-saturated felt containing asbestos fibers, used as an underlayment beneath shingles or as a waterproofing membrane on flat roofs
• Asbestos tar paper — Similar to roofing felt, used as a moisture barrier on roofs and walls. Commonly layered with hot tar during built-up roofing installation
• Asbestos roll roofing — Continuous rolls of asbestos-reinforced asphalt roofing used on low-slope roofs and outbuildings

Symptoms from asbestos roofing exposure mirror those of other asbestos-related diseases, appearing decades after exposure:³

• Chronic cough — Persistent dry cough that does not respond to typical treatments
• Shortness of breath — Progressively worsening dyspnea, initially only with exertion
• Chest or shoulder pain — Dull, persistent pain that may indicate pleural disease or tumor growth
• Hoarseness or difficulty swallowing — May occur with advanced thoracic disease
• Weight loss and fatigue — Systemic symptoms associated with malignancy

Asbestos roofing materials release fibers through several mechanisms:¹

• Natural weathering — Decades of UV exposure, rain, wind erosion, and temperature cycling gradually break down the surface matrix, exposing embedded asbestos fibers to the elements
• Cutting and drilling — Using power saws or drills on asbestos roofing generates high airborne fiber concentrations
• Breaking and impact — Walking on brittle asbestos cement shingles or dropping them during removal causes fractures that release fibers
• Tear-off operations — Removing old asbestos roofing during re-roofing projects is one of the highest-exposure activities
• Storm damage — Hail, wind, and falling debris crack and fragment asbestos roofing materials, releasing fibers into the environment

Groups with elevated risk from asbestos roofing exposure include:³

• Roofers — Workers who installed, repaired, and removed asbestos roofing materials, especially those who performed tear-offs without wet methods or respiratory protection
• Demolition workers — Crews who demolished buildings with asbestos roofing without proper abatement procedures
• Construction laborers — Workers who cut and fitted asbestos roofing products on job sites
• Homeowners — Individuals who performed DIY roofing repairs or removal on homes with asbestos shingles or felt
• Gutter cleaners and maintenance workers — Personnel who disturbed weathered asbestos roofing material while performing routine building maintenance

Evaluation of suspected asbestos roofing-related disease includes:⁴

• Detailed occupational history — Documentation of roofing work, including the types of materials handled and the duration of exposure
• Chest imaging — X-ray and CT scan to identify pleural plaques, thickening, effusions, or masses
• Pulmonary function testing — Measurement of lung volumes and gas exchange capacity
• Biopsy — Tissue sampling if imaging reveals suspicious lesions or if mesothelioma is suspected

Treatment is determined by the specific disease that develops from asbestos roofing exposure:⁴

• Mesothelioma — Multimodal therapy including surgery, chemotherapy, immunotherapy, and radiation based on stage, histology, and patient performance status
• Lung cancer — Standard oncologic treatment including surgery, chemotherapy, targeted therapy, immunotherapy, and/or radiation
• Asbestosis — Supportive care with oxygen therapy, pulmonary rehabilitation, and management of complications
• Pleural disease — Monitoring, drainage, or pleurodesis as indicated by symptoms and disease progression

Outcomes for individuals exposed to asbestos roofing materials depend on cumulative exposure and the resulting disease:⁴

• Roofers with heavy exposure — Studies show significantly elevated rates of mesothelioma and lung cancer among roofers who worked with asbestos-containing materials for extended periods
• Homeowners with brief exposure — Short-term exposure during a single roofing project carries relatively low risk, though no threshold of safe asbestos exposure has been established
• Mesothelioma — Median survival of 12–21 months, consistent across all exposure sources
• Weathering-related environmental exposure — Residents living under aging asbestos roofing face low-level chronic exposure; population-level health impact is difficult to quantify but is considered lower than occupational exposure

Safe management of asbestos roofing materials requires proper handling and regulatory compliance:¹

• Test before removal — Have roofing materials tested for asbestos content before any repair or removal work on pre-1980 buildings
• Roof-over option — In many cases, new roofing can be installed over intact asbestos shingles, avoiding the exposure risk and cost of removal. Local building codes may limit the number of allowable roof layers
• Wet methods — If removal is necessary, keep materials wet to suppress airborne fiber release
• Intact removal — Remove asbestos roofing materials in whole pieces whenever possible rather than breaking them. Use hand tools to minimize breakage
• Licensed contractors — Use certified asbestos abatement professionals for removal projects, with proper containment, worker protection, and regulated waste disposal