What Contractors Need to Know About Asphalt Emulsion
Asphalt emulsion sealer is now the industry standard for protecting and maintaining asphalt surfaces after the coal tar ban. It bonds with the pavement, stays flexible over time, and provides a safer alternative for crews and the environment.
Below are the most common contractor questions about asphalt emulsion, including performance, equipment, application, and troubleshooting.
Key Takeaways
- Coal tar sealer is banned across Canada
- Asphalt emulsion is the new industry standard
- Modern AE performs equal or better when applied correctly
- Proper mix design and application are critical
- Equipment compatibility depends on the product type
The Coal Tar Ban and Industry Shift
These are the most common questions about the transition away from coal tar. Is coal tar banned in Canada? Yes, the ban on coal tar emulsion sealer is in effect across Canada due to high concentrations of polycyclic aromatic hydrocarbons (PAHs) — compounds linked to health and environmental harm. This is not a phase-out or a recommendation — it is a ban. You cannot legally purchase or apply coal tar emulsion sealer for residential or commercial pavement work in Canada. Is the coal tar ban temporary? No. This is a permanent regulatory change. Everything west of the Mississippi River in the US has been under similar bans for years. Canada has caught up. Asphalt emulsion is the standard for sealcoating in most of North America, and that’s not changing. I tried asphalt emulsion years ago and didn’t like it. Has anything changed?Yes. The asphalt emulsion available today is completely different from what was used 15 to 20 years ago. Earlier products were not well suited for colder climates and often underperformed. Modern formulations use improved raw materials, better emulsifiers, and optimized viscosity, resulting in better flow, stronger performance, and more consistent results. What is the difference between asphalt emulsion and coal tar sealer?
Asphalt emulsion is made from asphalt binder and bonds with the pavement, while coal tar is a byproduct of coal processing. Asphalt emulsion is safer, more flexible, and now the industry standard.
Asphalt Emulsion Performance
These questions focus on how asphalt emulsion performs in real-world conditions. Does asphalt emulsion perform as well as coal tar? Yes. Modern asphalt emulsion is designed to bond better to pavement and stay flexible over time. When applied correctly, it delivers equal or better durability, especially in areas with temperature swings. What coverage rate can I expect with asphalt emulsion? Will it hurt my profitability? Most asphalt emulsion sealers cover around 100 square feet per gallon in ready-to-use form. This is comparable to, or better than, typical coal tar coverage when mixed properly. Will the colour look different to customers? When first applied, asphalt emulsion may look slightly brown compared to coal tar. Once fully cured, it dries to a deep black finish that most customers will not notice any difference from. Are tire marks still a problem with asphalt emulsion? Modern formulations have greatly reduced tire marking. Tire marks are also more likely when the material has not fully cured, especially in cooler or shoulder-season conditions. When applied correctly and allowed to cure, tire marks are minimal. Using polymer additives can further improve resistance.Equipment and Compatibility
These questions help contractors understand what equipment is needed. Can I use my existing sealcoating equipment with asphalt emulsion? In most cases, yes. Standard asphalt emulsion like SealMaster MasterSeal works with most existing spray systems. However, your tank, lines, and pumps must be fully cleaned before switching from coal tar. Do I need a different pump for asphalt emulsion? It depends on the product. Standard asphalt emulsion works with most pump types. Polymer-modified asphalt emulsion like SealMaster PMM requires a diaphragm pump and will not work properly with centrifugal or banjo pumps. What happens if I mix coal tar and asphalt emulsion in the same tank? The material will clump and coagulate, which can clog your system and damage equipment. A full cleanout is required before switching products. I heard AE is harder to work with — pumps clog, it’s thick, it’s a nightmare. Is that true? This was true of older AE formulations. Manufacturers have invested heavily in reducing viscosity without sacrificing solids content. The material flows better than it used to through diaphragm pump setups. That said — Polymer Modified AE such as PMM does NOT work through centrifugal or banjo pumps. If you’re running that type of equipment, you’ll need to upgrade to a diaphragm pump. This is a one-time equipment investment that actually improves your overall operation.Asphalt Emulsion Application Best Practices
These questions cover how to apply asphalt emulsion correctly. Does AE forgive shortcuts like coal tar did? Honest answer: No. AE rewards proper application and punishes shortcuts. If you overdilute it, it will fail. If you spray heavy coats in shaded areas without enough heat to cure, it will fail. If you don’t agitate and your sand settles, you’ll get inconsistent results, poor texture, and uneven performance. BUT — this is actually a good thing for contractors who do the job right. Those who cut corners will struggle. Professionals who follow the guidelines will produce results that last and build their reputation. How should I apply asphalt emulsion in shaded areas? This is one of the most important practical differences. Coal tar was tolerant of cool, shaded surfaces. AE is not. In any area that doesn’t get direct sun — building shadows, overhangs, tree cover — you should BRUSH the material rather than spray it. Brushing controls the application thickness and ensures the sealer sets properly even on a cooler surface. Spraying a heavy coat in the shade and hoping it cures is how you get failures. What temperature should I apply asphalt emulsion? Both air and surface temperatures should be at least 10°C (50°F) and rising. Applying in colder conditions can lead to improper curing and poor results. A good field check: lay your forearm flat on the pavement. If it feels cold compared to your skin, wait. Early morning applications in cool weather need extra caution — especially in shaded spots. In peak summer heat, make sure you’re diluting enough (especially with concentrate formulas) as water evaporates fast from a black tank. When should you not apply asphalt emulsion?Avoid applying in cold temperatures, high humidity, or shaded areas without proper technique. These conditions slow curing and can lead to failure.
Commercial Applications
Is the process different for two-coat applications with asphalt emulsion? Yes, but it is often more efficient. Apply the first coat at 70 to 80 percent coverage, wait at least 4 hours and perform a scuff test, then apply the full second coat. Unlike coal tar, asphalt emulsion does not require a long off-gassing period. Once it looks dry, it is ready for the next coat, which speeds up production on commercial jobs.Customer Service and Safety
How do I explain the switch to asphalt emulsion to customers? Keep it simple. Let them know the product has changed due to regulations and that the new sealer is safer, cleaner, and performs just as well. Most customers care about the final result. Examples:- “We’ve upgraded to asphalt emulsion, it’s the new industry standard.”
- “It’s a safer, cleaner product with no harsh chemicals.”
- “It performs just as well and cures faster.”
Storage and Maintenance
These questions cover handling and long-term use. Can I store asphalt emulsion over winter? Yes, as long as it is stored indoors and does not freeze. Before reuse, it should be fully agitated and checked for contamination. How often should I clean filters and strainers? Daily. Cleaning filters at the end of each workday helps prevent clogs and keeps your system running smoothly. Can I pour leftover material back into my main tank?No. Reintroducing stored material is one of the most common ways to contaminate your tank with bacteria. Always keep stored product separate.
Troubleshooting and Tank Issues
These questions help identify and fix common problems. Why does my tank smell like rotten eggs? This is a sign of bacteria contamination. It needs to be treated immediately before it affects your material and application quality. How do I treat bacteria in a sealcoating tank? Mix 1 part pool shock (standard pool chlorine) with 1 part water and add to the tank. The ratio is:- 1:1 Pool Shock to Water: Mix equal parts pool shock and water before adding to tank
- 1 gallon pool shock per 1,000 gallons of material in the tank (Example: 4 gallons pool shock diluted in 4 gallons of water for an 8,000 gallon tank)
What Asphalt Emulsion Products Should You Use?
Choosing the right product depends on the job.
- MasterSeal is ideal for residential driveways and standard commercial work
- PMM (polymer-modified) is better for high-traffic areas
For best results, combine your sealer with sand and additives like Top Tuff to improve durability and traction.
Need Help Choosing the Right Setup?
If you’re switching from coal tar or want to improve your results with asphalt emulsion, our team can help you choose the right sealer, equipment, and mix design.
