Types of Sealcoating

Asphalt pavement fades in appearance over time, but seal coating can restore its original color and smooth out small cracks. It also helps prevent water from entering these cracks, which can cause damage.

Workers use Personal Protective Equipment (PPE) like boots, coveralls, gloves and safety glasses while sealcoating. The sealer can release fumes, so workers should take breaks when needed. Visit Website to learn more.

As the name implies, oil-based tars contain a petroleum substance and are used to seal asphalt. They offer excellent weather protection and resist chemicals that damage asphalt, such as de-icers. They are also able to withstand heavy traffic. However, these types of tars do not last as long as other types and will need to be re-applied more frequently.

Coal tar sealcoat is another popular type of sealcoating. This material is similar to the other types, but it does not last as long and it may not be allowed in some cities due to high PAH levels. However, this coating is water resistant and does not fade as quickly as other types of sealcoats, so it is a good choice for residential driveways.

The coal tar emulsion sealcoat is made from a mixture of water and a petroleum-based substance called coal tar pitch. This product is the oldest and most traditional sealcoat on the market. It is also the most expensive type of sealcoat, but it offers many advantages, including excellent durability and longevity.

Asphalt emulsion sealcoat is similar to coal tar in that it is also made from a mixture of water and tar, but the tar content is lower. This sealcoat is the most common, as it provides an economical alternative to coal tar emulsion and other petroleum-based products. It does not last as long as coal tar or oil-based sealers, but it offers some important benefits that make it a great choice for commercial properties.

This type of sealcoat is designed to protect pavement from gasoline and other oil spills, as well as to prevent oxidation. It is also useful for protecting against cracks and abrasions. These tars are often used in parking lots and highways.

This type of sealcoat is not suitable for asphalt that has recently been repaired or resurfaced. It is also not recommended for areas that are prone to heavy rains, as the moisture can cause the sealcoat to wash away. The best way to avoid this is to pressure wash the asphalt before you have it sealed. It is also a good idea to have your asphalt sealcoating done during the day so that sunlight can evaporate the water molecules before the sealcoat dries.

Latex Tar

Latex additives are used in tar sealcoats to boost and compliment the properties of the tar. They are primarily composed of a dispersion of rubber/polymers in water (latex or emulsion) and minor amounts of specialty chemicals. These additives help to keep sand/aggregate evenly suspended, produce a smoother texture and fill minor surface defects in the asphalt. The addition of latex to a sealcoat mix also helps to improve its flexibility, toughness, fuel & chemical resistance and overall longevity.

Refined Coal Tar (RTS) and asphalt-based sealers are both used in the preparation of home driveways, parking lots, and commercial facilities such as airports, gas stations etc. Refined coal tar is derived from the distillation of bituminous coal. It is also a byproduct of the steel making industry and is often used as an ingredient in the production of paint, inks and other chemicals.

RTS is a thick black liquid that contains sulfur and carbon black as well as other components that are naturally occurring in the crude oil of which it is made. RTS is generally preferred by manufacturers and professionals for its superior durability, versatility and performance. It is highly resistant to petroleum based and deicing salt solutions, jet fuel, gasoline and other hydrocarbons. It is also less sensitive to temperature fluctuations, allowing it to be applied at temperatures as low as 32 degrees Fahrenheit.

The majority of sealcoat manufacturers now offer RTS-based products in addition to their asphalt-based product lines. The choice of which type to use is generally a matter of price and availability. In most cases, however, it is recommended that professional sealcoat contractors use a RTS-based product.

When choosing a sealcoat, it is important to read the material safety data sheet (MSDS) carefully. It is recommended to only use products that are free of coal tar; refined coal tar or coal tar pitch as these products are known to be a significant contributor to the accumulation of polycyclic aromatic hydrocarbons (PAHs) in urban waterways. Many major retailers of home improvement products now offer a wide range of asphalt, acrylic and latex-based tar sealcoats that are PAH free.

Coal Tar

Many parking lots and driveways are coated with coal tar sealcoat, a dark, viscous liquid, to maintain and improve the appearance of underlying asphalt pavement. While the material offers considerable pavement protection, it also poses significant environmental and health-related risks. Coal tar-based sealants release high levels of polycyclic aromatic hydrocarbon compounds, which are known and probable carcinogens. As a result, their use is being phased out in many areas.

Coal tar is a thick black byproduct of the coking, liquefaction or gasification of coal. It can be separated into 12 grades of viscosity. The most viscous grade, RT-12, is used to make coal-tar sealcoat. This product contains toxic PAHs that leach from the coating into the ground and waterways during application, drying and evaporation. These chemicals can then contaminate surface and groundwater and cause cancer, birth defects, and other health problems in humans.

The chemical also releases PAHs into the air during application and drying, where they can be inhaled by workers. This can lead to a variety of health problems, including respiratory and cardiovascular issues. The chemicals can also be absorbed through the skin. Coal tar is highly flammable and produces toxic fumes during the application process. Workers must wear breathing masks and protective clothing when working with this product.

Runoff from coal tar-sealed parking lots can carry these PAHs into streams, lakes and marine waters. This can harm fish, other aquatic life and humans who come into contact with the contaminated water. Studies using a range of “forensic” methods have found that coal-tar-based sealcoat is the leading source of PAHs in urban stream and lake sediment.

In addition to causing cancer, PAHs can be transferred from a coated driveway or parking lot to nearby homes. As the material dries, it can leave tiny particles behind on shoes and tires that are then tracked into homes. These particles can also mix with household dust and be inhaled or ingested by family members.

Researchers have found that breastfed infants may absorb pyrene, a PAH from coal-tar sealcoat, through skin-to-skin and mouth contact with their mothers. This toxicity can disrupt the mother’s immune system, resulting in lowered antibodies and other health complications.

Acrylic

In addition to being a durable and cost-effective material sealcoats are also able to resist oil stains, gasoline spills, antifreeze, salt and other damaging chemicals. This is due to their high content of styrene-butadiene rubber. These rubber additives are whitish in color when wet but dry clear and have a pully texture similar to acrylic medium used for painting.

The styrene-butadiene sealcoat additives help improve the adhesion of asphalt to the pavement surface, as well as to other ingredients in the sealcoat mixture. They are resistant to a broad range of chemicals and solvents, including hydrocarbons, fats, gasoline, kerosene, lubricating oils, hydraulic fluids and many mild acids. These additives are more commonly used in coal tar and asphalt emulsion based sealcoats, but they can also be added to refined tar and asphalt slurry sealcoats.

Refined tar and asphalt slurry based sealcoats are commonly supplied as concentrates (undiluted) to be mixed with water, silica sand and sealcoat additives in the appropriate proportions to achieve the required application consistency according to the manufacturer’s recommendations. The additives should be selected with the proper understanding of their properties and overall contribution to sealcoat longevity.

When mixing these sealcoat materials, workers must be careful not to contact any of the toxins. Repeated exposure to these carcinogenic materials can lead to skin or lung damage, so it’s important that workers wear protective gear and thoroughly clean their hands and equipment afterward. It’s also a good idea to use a power mixer rather than hand-mixing, as this will allow the mixture to be blended more quickly and evenly.

It’s also crucial to properly prepare the surfaces before applying sealcoat. Workers should remove any debris or potholes and patch any areas of the pavement that need it, sanding the surface in preparation for the new coating. They should then let the sealcoat dry for 24 to 48 hours before allowing traffic back on the road or reapplying line striping.

While sealcoating is a great way to protect your pavement, you need to partner with a contractor who will take the time to do it right. They should be knowledgeable about the different types of materials and their respective advantages and disadvantages, and they should stand firmly behind their work.