Asbestos in Roofing Felt: What to Know

Many older homes and buildings have roofing felt made with asbestos. Asbestos in roofing felt can be dangerous if the material is disturbed and fibers become airborne. People who live or work in these buildings may not even know that their roofs could put their health at risk.

Roofing felt was once a popular choice because asbestos made it strong and fire-resistant. Even though this product is no longer used today, it is still found in many older roofs. Knowing how to identify and manage asbestos roofing felt is important for safety.

Why Was Asbestos Used in Felt?

Asbestos was added to roofing felt because it made the material stronger and more fire-resistant. The tiny fibers helped the felt last longer, even in bad weather such as high winds and rain from hurricanes or tornadoes.

Builders liked asbestos for materials because it was cheap and easy to mix with other items. Asbestos is a mineral found in the earth’s soil, and there were asbestos deposits throughout the United States. Asbestos also can stop water from getting into buildings through the roof.

Main Benefits of Asbestos in Roofing Felt

• Fire resistance – Does not burn easily
• Strength – Makes felt tougher
• Durability – Helps felt last longer
• Water resistance – Keeps moisture out

The main type of asbestos found in roofing felt is called chrysotile, which is sometimes called “white asbestos.” Chrysotile asbestos is the most common type of asbestos and the only type still imported into the U.S. as of 2023.

In 2024, the U.S. Environmental Protection Agency (EPA) announced a ban of chrysotile asbestos. Fortunately, most construction companies have moved away from using asbestos in any new buildings or renovations of old buildings.

A table can help show the reasons for adding asbestos:

Types of Asbestos Felt Products

Asbestos was once used in many building materials for its durability and resistance to fire, water and chemicals. These products are still present in older buildings, creating health risks if disturbed.

The types of felt products containing asbestos are: roofing felt (tar paper) and underlayment; vapor barriers and flooring layers; and paper products in industrial settings.

Roofing Felt and Underlayment

Roofing felt, also called tar paper, was commonly made with asbestos fibers during much of the 20th century. Asbestos adds strength and makes the felt fire-resistant. Contractors used it under roofing tiles, shingles and other roofing materials as a protective barrier.

This felt was installed in overlapping layers to prevent water leaks and protect the roof deck. It was especially popular for flat or low-slope roofs in commercial buildings and some homes. In addition to roofing tiles and shingles, asbestos felt sometimes accompanied roofing tile or roofing products like flashing and sealants.

Manufacturers labeled asbestos roofing felt under many brand names, but all pose similar risks if damaged or deteriorating. The felt can release tiny asbestos fibers into the air if cut, torn, or removed.

Vapor Barriers and Flooring Layers

Some vapor barriers and underlayment used in construction during the 20th century also contain asbestos felt, especially beneath vinyl floor tile or linoleum. These products help control moisture and provide a smooth base for finish flooring. Vinyl floor tile installations up until the 1980s often used an adhesive strip or entire felt layer with asbestos for stability and fire resistance.

Older flooring assembly might include asbestos-containing millboard, which is a thick, stiff sheet made for insulation and fireproofing. Some block insulation forms and flooring felts were installed together to resist mold and dampness below floors. Removal or repair work may disturb these layers, making asbestos fibers airborne.

Flooring felt and vapor barriers can be hidden underneath newer materials, making their location and condition hard to check without professional help.

Paper Products in Industrial Settings

Industrial settings used asbestos-containing paper products almost as frequently as homes and businesses. Pipe insulation and block insulation can have a paper or felt component made with asbestos, forming a barrier around piping to hold in heat or protect against fire.

Asbestos millboard and composite paper products appear in equipment insulation, circuit boards and gaskets. In factories, these papers line machines, wrap pipes, and sometimes help form joint compounds or backing for ceiling tiles and textured paints.

Some roofing felts and industrial wraps for large machinery also contain layers of asbestos paper for extra strength. Old paper products in these settings can still crumble and release fibers if disturbed. Inspectors and maintenance workers should use caution if they suspect materials contain asbestos.

Who Was Most at Risk of Asbestos Exposure From Roofing and Flooring Felt?

People who worked with or around asbestos-containing roofing felt during the 20th century faced the greatest chance of coming into contact with dangerous fibers. Today, inspectors, maintenance workers and repair workers may find old asbestos hiding in buildings.

Risk depends mainly on the type of job and the amount of direct handling of asbestos products. The at-risk jobs include: roofers and construction workers; paper mill workers; and demolition crews and renovators.

Roofers and Construction Workers

Roofers and construction workers were especially at risk because they installed, cut, and repaired roofing felt during the 20th century that often contained asbestos. Cutting, hammering, or tearing old felt released fibers into the air. These workers usually performed their duties outdoors, but dust from asbestos could still be dangerous. Data shows a link between construction workers and asbestos exposure.

Common tasks leading to exposure could include:

• Removing old roofing felt
• Installing new layers
• Cutting felt to fit roof edges

Roofers might have worn little to no protective gear before the 1980s, making inhaling or swallowing asbestos fibers even easier. Inhaling these fibers could later cause lung problems or diseases like mesothelioma.

Paper Mill Workers

Paper mill workers who made roofing felt decades ago ran a high risk of asbestos exposure, especially before stricter regulations were enacted. They often handled raw asbestos fibers directly, mixing them with wood pulp to create heat-resistant felt.

Large machines used in this process produced dust, which spread through the air and settled on surfaces. Workers could breathe in these fibers or carry them home on their clothing.

Tasks – ones which still occur today – like cleaning old equipment, shoveling asbestos on the floors, and repairing old machinery all increase exposure risk. Problems with ventilation in the mills sometimes make controlling airborne fibers even harder.

Demolition Crews and Renovators

Demolition crews and renovators working on older buildings also face serious risks. Tearing out or disturbing old roofing felt could release asbestos fibers that were trapped inside the material for decades. This is an asbestos exposure risk even today, as most buildings demolished or renovated are older and more likely to contain the mineral.

These jobs often require breaking, scraping, or removing roofing layers, which puts workers in direct contact with asbestos debris. If proper safety steps are not followed, clouds of dust could spread indoors and outdoors.

Key risk factors included:

• Lack of protective masks or clothing
• Poor ventilation
• Lack of training on asbestos hazards

People doing renovation work in homes built before the 1990s are also at risk when they cut, sand, or drill into asbestos-containing felt.

How Asbestos Exposure Occurred With Felt

Asbestos is a sturdy mineral, but it is made of many microscopic fibers woven together like a cloth. When the mineral is disturbed – such as from maintenance work, demolition work or weather events – the fibers can splinter and separate.

Since the fibers are weightless, they float in the air. These fibers can be inhaled or swallowed by workers or others in the area – including home residents or office workers – and they can get stuck in the body and cause irreversible harm.

Workers and homeowners can come into contact with asbestos through regular handling of roofing felt. Dust created during work often contains asbestos fibers if the material is old or damaged.

Cutting or Ripping Felt Sheets

Asbestos fibers were tightly bound in roofing felt, but cutting or tearing the sheets releases these fibers into the air.

This process could happen during installation, repairs or demolition. Using hand tools or power saws to shape or remove felt increases the release of dust, especially if the material is dry and brittle. Workers nearby could breathe in the airborne fibers.

No amount of asbestos exposure is safe, but workplace rules allow some fibers in the air. For example, the permissible exposure limit (PEL) set by OSHA is 0.1 fibers per cubic centimeter of air, averaged over eight hours. Even the tiniest amount of asbestos entering the body can lead to severe diseases, including types of cancer.

Key risks included:

• Not using protective equipment
• Working in closed spaces
• Cutting old, brittle felt

Dust from Old or Damaged Materials

Over time, roofing felt could become cracked or broken from sun, rain or heavy use. As the mineral breaks down, asbestos fibers splinter and float in the air.

People working on older roofs or cleaning up debris can stir up this dust. Sweeping, scraping, or renovating without wetting the surface increases dust levels and risk.

Airborne asbestos poses a hazard in these conditions:

• Attics and ceilings with old felt
• Wind-blown debris from torn-off roofs
• Sheds or barns with exposed, decaying felt

Even low levels of dust could release enough fibers to go past safe exposure limits, especially without proper safety steps.

Industrial Machinery Contamination

During the 20th century, when asbestos use was at a peak, factories used machines to cut, press, and roll roofing felt. These machines sometimes broke down the felt, sending up fine dust full of asbestos fibers.

Operators, maintenance staff, and cleaners risked exposure during machine work or when cleaning up loose dust and debris.

Proper ventilation and dust control equipment were often missing or weak in older facilities. Workers near these machines could breathe in airborne fibers without knowing. Over time, asbestos could also settle on uniforms and tools, allowing workers to carry fibers to other areas of the factory or even back to their home.

Regular cleaning and the use of protective clothing are key steps, but they were not always enforced or available in industrial settings.

Health Risks Linked to Asbestos Felt

When asbestos fibers from roofing felt become airborne and are inhaled, they can get trapped in the lungs. This can increase risks for serious diseases over time, especially for people who work with or around asbestos without using protective equipment.

The health risks associated with asbestos exposure are mesothelioma, lung cancer, ovarian cancer and a lung scarring disease called asbestosis.

Mesothelioma and Lung Cancer

Mesothelioma is a rare cancer caused 100% by inhaling asbestos fibers. It begins in the lining of the lungs, abdomen or heart and can take decades to develop after exposure. People who worked with or removed asbestos roofing felt have a higher risk compared to the general population.

Lung cancer can also be caused by asbestos exposure. Risk is higher in those who smoke. Inhaling asbestos fibers damages lung tissue, which increases the chance of cancer developing over time.

Main ways people are exposed include:

• Installing or removing old roofing felt
• Cutting or tearing felt, which releases fibers
• Working without respirators or other protective equipment

Both conditions are hard to treat and usually have a poor outlook, especially when not detected early.

Asbestosis

Asbestosis is a lung disease caused by breathing in asbestos fibers over a period of years. It leads to lung scarring (fibrosis), which makes breathing hard and limits lung function. Symptoms may not appear until many years after first exposure.

People with asbestosis may have:

• Shortness of breath
• Persistent cough
• Chest tightness

Chronic exposure can also cause other respiratory illnesses. Using respirators and protective equipment during roofing felt work can reduce the risk. Protecting the lungs is important, as these diseases can be permanent and even life-threatening.

Identifying and Managing Asbestos Felt Today

Old roofing felt can contain asbestos, which poses health risks if disturbed. Knowing how to find and handle this material is important for homeowners, home residents, office managers and construction crews or demolition professionals.

Found in Homes and Offices Built Before 1990

Many homes and other buildings built before 1990 may have roofing felt containing asbestos. This material was often used because it is durable and resistant to heat.

Signs that roofing felt may contain asbestos include original construction dates before 1990 and labels or manufacturer’s marks mentioning “asbestos.” However, visual checks alone cannot confirm the presence of asbestos.

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Homeowners or other home residents should not try to remove or handle roofing felt themselves. The same is true for office building owners or managers.
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It is safest to leave suspected asbestos materials undisturbed and intact. If renovations or repairs are planned, an asbestos inspection should be done first. Certified asbestos inspectors are trained to spot possible asbestos-containing felt and decide if testing is needed.

Testing and Abatement

Proper identification starts with asbestos sampling. Only licensed asbestos inspectors should collect samples of felt for laboratory analysis. This process checks for asbestos fibers with methods like Polarized Light Microscopy (PLM).

If asbestos is found, professional asbestos removal – called asbestos abatement – is required. The removal of asbestos involves:

• Setting up work areas with plastic sheeting
• Using personal protective equipment (PPE)
• Sealing and carefully disposing of materials

Building owners and home residents should never try to remove asbestos roofing felt themselves because fibers can be released into the air. Professional abatement teams follow strict rules to prevent contamination and protect everyone’s health.

Legal Options for Workers Exposed to Asbestos Felt

Workers who were exposed to asbestos in roofing felt have legal rights to seek compensation for mesothelioma or other asbestos diseases. They may be able to seek financial help or file legal claims, depending on their health and job history.

Eligibility for Asbestos Compensation

People who developed illnesses, such as mesothelioma or asbestosis, after working with asbestos roofing felt or otherwise being exposed to asbestos from roofing felt, may qualify for compensation. This includes workers in construction, roofing, demolition or anyone who handled asbestos products on job sites. It also includes homeowners or other residents exposed during repair work.

Eligibility often depends on factors such as:

• The type and length of exposure
• Medical diagnosis confirming an asbestos-related disease
• Proof of work history with asbestos felt

Asbestos regulations require employers to protect workers and keep records. Some local laws, like asbestos disclosure laws, need property sellers or landlords to share any known information about asbestos.

A successful claim may cover medical costs, lost wages, and pain and suffering. Family members may also have legal rights if a loved one who was exposed to asbestos felt has passed away due to asbestos disease.

Asbestos Trust Fund Claims and Lawsuits

The two main methods of seeking asbestos compensation are filing a lawsuit and filing an asbestos trust fund claim. Asbestos trust funds are bank accounts created by bankrupt companies to ensure victims are compensated appropriately for their diseases.

Filing a claim with an asbestos trust fund is usually less complex than a lawsuit. Trust funds use set rules to decide if a worker qualifies and how much money they can get.

Key steps in a trust fund claim:

Asbestos exposure lawsuits are filed when the responsible company is actively operating. Lawsuits may go against employers, manufacturers, or others. It is important to understand deadlines (statutes of limitations) for filing legal claims. Legal help from a lawyer with asbestos experience can guide workers through both options.

Final Thoughts: A Hidden Layer and Serious Risk

Roofing felt once seemed like a harmless part of homes, offices and other buildings,, but asbestos was often added to old felt for strength and fire resistance. Many buildings constructed during the 20th century still have this material under shingles or tiles.

People working on these roofs may not know the risk. Asbestos fibers are invisible and can be released into the air when felt is disturbed or damaged. This can happen during repairs or removal.

Serious health problems can result from breathing in asbestos fibers. Diseases like asbestosis, lung cancer and mesothelioma are linked to asbestos exposure.

Anyone working with old roofing felt should use caution. While new uses of asbestos felt are not likely, repair and demolition crews may release fibers from decades-old felt. Homeowners and residents may also release fibers during do-it-yourself work.

It is best to call professionals trained in asbestos removal.

Frequently Asked Questions Asbestos in Roof Felting

Asbestos was once a common material in roofing felt and related products. Testing, safety and removal guidelines help reduce incident risks when working with suspected asbestos materials.

Sources & Author

About the Writer, David Statman

David Statman is a Content Writer for Mesothelioma Guide. He received both his bachelor's and master's in journalism from West Virginia University, and has been in medical publishing since January 2022. He previously worked in sports journalism, primarily reporting on West Virginia sports for a number of publications.

He lives in Delaware with his wife, dog and two cats, and avidly competes as a professional wrestler in the Philadelphia area.