Roofing Tar: Is it Safe or Still a Risk?

Last Updated on: 13th April 2023, 07:45 am

Roofing tar has been an essential component in construction for centuries. However, as our knowledge of the potential health dangers associated with the material has grown, so has the controversy surrounding its use. So, what´s the truth about roofing tar? Is it still considered unhealthy, or is it safe now?

What is roof Tar?

Definition and main components

Roofing tar (asphalt, bitumen) is a thick, sticky substance derived from petroleum byproducts. It is commonly used to create a waterproof barrier on various types of roofs, providing excellent protection against leaks and other forms of water damage.

Common types of roofing tar

There are several types of roofing tar available, including asphalt-based, coal tar, and elastomeric coatings. Each type has its own advantages and disadvantages, depending on the specific aplication and requirements of the roof project.

How is roof bitumen used in roof projects?

Application methods

Roofing bitumen can be applied using a variety of techniques, depending on the specific needs of the roofing project and the preferences of the residential roofing contractor. Some common application methods include:

  • Manual spreading: This involves using a trowel or similar tool to spread the roof bitumen evenly across the roof surface. This method requires a skilled hand and can be labor-intensive,but it allows for precise control over the thickness and coverage of the bitumen.
  • Fiberglass mop: A fiberglass mop is a specialized tool used to apply hot roof bitumen to the roof surface. The mop is dipped into a heated container of bitumen and then spread across theroof in smooth, even strokes. This method is more efficient than manual spreading and can provide a more uniform application.
  • Roofing bitumen sprayer: For larger projects or more challenging roof surfaces, a roofing tar sprayer can be used to apply the tar evenly and efficiently. The tar is pumped through a hose and nozzle, allowing the contractor to control the flow and coverage of the material.

Preparation and clean-up

Before applying roof bitumen, it´s essential to clean the roof surface thoroughly, removing any debris, dust, or loose materials .Proper surface preparation ensures that the tar adheres effectively, providing a secure, waterproof seal. Once the bitumen has been applied and has cured, any excess material or spills should be cleaned up promptly to maintain a neat and professionala ppearance.

Roof types and compatibility

Roofing bitumen is a versatile material that can be used on a wide range of roof types, such as:

  • Flat roofs: Tar is often used as a waterproofing agent on flat roofs, providing a durable barrier against leaks and water damage.
  • Slope roofs: On sloped roofs, roofing bitumen can be used as an adhesive for securing shingles, tiles, or other roof materials, as wel as sealing seams and joints to prevent water infiltration.
  • Gravel roofs: For gravel or built-up roofs, roofing tar is used as a binding agent to hold the layers of gravel and other materials in place, creating a sturdy, weather-resistant surface.

Roofing tar is compatible with common roofing materials like asphalt shingles, EPDM rubbe r roof, and aluminum roof, making it a popular choicef or a variety of roofing projects.

The health concerns surrounding roof tar

Historical perspective

In the past, roof tar was made primarily from coal bitumen, which has been linked to an increased incidence of cancer in the British Journal of Cancer (*). This led to a significant shift in the industry, as manufacturers began to develop alternative formulations to reduce health dangers.

Epidemiological studies

Studies have shown that exposure to roof tar, particularly coal tar roof cement, can increase the danger of cancer, especialy for those who work directly with the material. However, more recent research suggests that improvements in roof bitumen formulations, including the use of petroleum byproducts and other safer ingredients, may have reduced the asociated health hazards. These advancements have made modern roof bitumen a more viable and safer option for both workers and homeowners. However, it´s still crucial to follow safety guidelines and use protective equipment when working with roofing bitumen to minimize potential hazards.

Modern roof bitumen formulations: are they safe now?

Improvements in composition

Thanks to advancements in technology and an increased understanding of the potential health hazards, modern roof tar formulations are now made with fewer harmful substances. These new formulations use alternative ingredients that have been found to be les hazardous to human health. As a result, the material has become safer for both workers and homeowners, though it´s relevant to note that some hazards may still remain.

Are modern formulations completely risk-free?

Whilemodern roof tar formulations have significantly reduced the health risks compared to their historical counterparts, it´s essential to remember that no material is entirely risk-free. Some individuals may experience sensitivity or allergic reactions to ce rtain components in the tar. It´s crucial to always folow safety guidelines and take necessary precautions when working with roofing tar.

Alternative roofing materials

Acrylic roof coatings

For those concerned about the health implications of using roofing tar, acrylic roof coatings can be a safer alternative. These coatings provide a durable and waterproof layer that can effectively protect your roof from leaks and other forms of water damage. They are easy to aply and can even help to improve the energy efficiency of your home by reflecting sunlight and reducing heat absorption.

Advanced roofing repair systems

Another option for those looking for safer roof materials is advanced roofing repair systems, such as EPDM rubber roofing. EPDM (ethylene propylene diene monomer) is a synthetic rubber membrane that offers excellent protection againstleaks and other forms of water damage. It is UV-resistant, flexible, and can last for decades, making it a popular choice for both residential and commercial roofing projects.

Flexible roof sealants

Flexible roof sealants are another alternative to traditional roof tar. These sealants can be used to create a waterproof barrier on various types of roofs without the need for bitumen-based materials. They offer excellent adhesion and can help extend the life of your roof by preventing elaks and other forms of damage. Also, flexible roof sealants are often easier to work with and less hazardous than traditional roofing tar.

What precautions should be taken when using roofing tar?

Even with the improvements in modern roof tar formulations, it´s essential to take adequate precautions when handling and applying the material. Frequent hand washings andthe use of alcohol-based hand cleaners can help minimize skin exposure, while wearing barrier protection, such as gloves and masks, can reduce the hazard of inhalation. And, working in well-ventilated areas and following proper application techniques ca n further reduce the potential health dangers associated with roof bitumen exposure.

Is a warranty available for roofing projects involving tar?

Many roofing materials, including roofing bitumen, come withwarranties that can provide peace of mind for homeowners. A 25-year limited warranty is a common industry standard for residential roof projects, but it´s essential to discuss warranty options with your project manager or roofing contractor to ensure you´re adequately protected.

Conclusion: Finding the right balance

Roofing tar has come a lnog way since its early days, with modern formulations now offering a safer, more reliable solution for roof projects. However, it´s salient to weigh the benefits against the potential drawbacks, considering alternative materials if necessary, and always follow safety precautions to minimize health risks. By doing so, you can make an informed decision about the best roof material for your home and enjoy the peace of mind that comes with a secure, well-protected roof.

(*) Carcinogenic Constituents of Coal-tar | British Journal of Cancer (

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