May 8, 2023

In any asphalt sealcoating process, there are two major choices for asphalt sealer- asphalt emulsion and coat tar sealers. The look and the finished product may appear similar, but are they? There are significant differences between the two and you’ll want to know what they are before your next asphalt sealing project. Coal tar has been deemed the industry standard for decades, but did you know that it can cause several health conditions? Did you know there’s a safer and eco-friendlier alternative? Because there is- asphalt emulsion. Keep reading to learn more about which is better between asphalt emulsion and coal tar sealcoating!

Key Takeaways:

  • While it offers considerable pavement protection, coal tar-based sealcoating is being phased out due to its high environmental and health-related risks. 
  • Asphalt emulsion is environmentally friendly since it produces few to no hydrocarbon emissions.
  • By applying an asphalt emulsion sealcoat, you can extend the lifespan of your pavement and lower the need for costly repairs.

What’s Sealcoating and Why Is It Important?

Sealcoating is a pavement maintenance technique that involves layering or spraying a protective layer onto the pavement to prevent damage. With careful application of sealcoating materials, you can maximize the life span of your pavements while keeping them aesthetically pleasing. Here’s why sealcoating is essential to your pavement:

Protection against Weather Elements

Sealcoats act as a protective barrier shielding asphalt from the harmful effects of UV rays, rain, and snow. They also help prevent water from penetrating the surface of the asphalt, which can cause it to expand and contract with temperature changes, leading to cracks and other forms of damage.

Protection against Heavy Traffic

Regular sealcoating is critical for commercial parking lots, where heavy vehicles and high traffic volumes can cause significant weathering & pitting on the pavement. Investing in sealcoating enables you to save money on repairs and ensure your lot remains safe and attractive.

Pavement Maintenance

Over time, exposure to the elements and vehicle traffic can cause asphalt to deteriorate, resulting in cracks, potholes, and other forms of damage. By applying a sealcoat, you can extend the lifespan of your pavement and avoid costly repairs.

Related: 8 Sealcoating Facts Every Asphalt Pavement Owner Should Remember.

Types of Sealcoats for Commercial Application

There are two main sealcoats for commercial application: asphalt emulsion and coal tar application. 

Asphalt Emulsion Sealcoating

Asphalt emulsion consists of asphalt, water, and a small quantity of an emulsifying agent. These components are inserted into a colloid mill machine, where asphalt is broken into tiny droplets. The emulsifier is a substance that helps keep asphalt droplets suspended and controls how long the suspension remains stable. This creates a liquid substance with variable consistency. 

The Pros of Asphalt Emulsion

Here are the benefits of asphalt emulsion:

More Aesthetically Appealing

Coal tar only produces a dark gray color. But asphalt emulsion brings out the beauty of your property with its pitch-black color. 

Not as Toxic as Coal Tar Sealer

Coal tar sealers contain high concentrations of PAHs. These compounds are known to cause irritation and cancer. 

Better for the Environment

Asphalt emulsion isn’t hazardous to humans, aquatic, and wildlife. But you should ensure that you dispose of any excess product properly to prevent it from becoming a pollutant. 

The Cons of Asphalt Emulsion Sealcoating

Here are some drawbacks of asphalt emulsion sealcoating:

  • Frequent Applications: It’s true that coal tar has an edge over asphalt when it comes to longevity.
  • Temperatures: For best results, you need to apply asphalt emulsion when temperatures are over 55°F.

Coal Tar-Based Sealcoating

A coal tar-based sealcoat is made by mixing coal tar, water, and other additives to create a black, tar-like substance. Coal tar is a byproduct of the coal industry. It contains high levels of polycyclic aromatic hydrocarbons (PAHs), toxic chemicals linked to cancer and other health problems. It can also release toxic fumes and particles during application and drying and contaminate waterways and soil when it is eroded by rain or runoff.

Why are Coal Tar-Based Seals Being Phased Out?

Although it offers considerable pavement protection, its use has more problems than benefits. In fact, coal tar sealcoating, which has been widely used is now banned in some areas, such as North Carolina, due to its potential risks to human health and the environment. Some of the potential risks associated with coal tar include:

  • Cancer: It contains high levels of polycyclic aromatic hydrocarbons (PAHs), which are toxic & carcinogenic chemicals that have been linked to cancer.
  • Respiratory problems: Coal tar can release harmful volatile organic compounds (VOCs), fumes, and particles during application and drying, leading to respiratory issues such as coughing, headaches, irritation, wheezing, and shortness of breath.
  • Water pollution: When coal tar is applied to a surface, rain, and runoff can wash away harmful chemicals and deposit them into nearby waterways, contaminating the water and harming aquatic life.
  • Soil contamination: Coal tar runoff can seep into the soil and contaminate the surrounding area, potentially affecting nearby plants and animals.
  • Air pollution: The fumes and particles released during the application and drying of coal tar can exacerbate air pollution, which can negatively impact human health and the environment.

Asphalt Emulsion vs. Coal Tar: Which’s Better?

When choosing between the two sealers, it’s essential to consider environmental impact, durability, and the specific needs of your asphalt pavement. Nonetheless, asphalt emulsions are more environmentally friendly than coal tar-based seals.

Need Pavement Sealcoating? Consult the Experts!

Are you looking for superior protection for your commercial pavement? How about a long-term solution protecting the surface from adverse weather conditions and harsh chemicals, such as deicers, oil spills, and more? Consider sealcoating your pavement with asphalt emulsion. 

At Paved Assets, we guarantee the highest quality and most eco-friendly sealcoats protecting your asphalt investments. We recognize the necessity of regular sealcoating to preserve asphalt pavement. Our experts will collaborate with you to develop a pavement maintenance plan that meets your financial constraints and timeline requirements. Get a free estimate now.