Types of Asphalt Sealers

The point of layering your driveway with asphalt sealers is to protect the surface area from wear and tear as the UV rays from the sun can cause the asphalt binding composition to breakdown overtime whereas regular rainfall and snow can cause the pavement to turn brittle and crumble. Generally, it is recommended that you apply a fresh layer of asphalt sealers every three years to keep your road looking newly paved. After all, regularly caring for and maintaining the condition of your driveway can potentially save you up to 100,000 in lifetime future repair costs.

Asphalt Emulsion Sealers

Asphalt emulsion sealers are asphalt-based and are popularly known as the environmentally-friendly alternative to protecting your driveway. However, it should also be noted that there are no known research or studies that have proven the pollution or hazards caused by paving one’s road with coal tar-based sealers. Asphalt-based sealants are better in terms of preserving air quality, smell better, prevent oxidization and do not cause skin irritation.

The drawback to applying asphalt emulsion sealers though is that it is prone to staining caused by oil or gas spillage. This sealer type also can only be applied between May to September for best curation time and are especially impossible to work on during the night time when the ambient temperature is at its lowest. The price of asphalt emulsion sealers is also extremely volatile due to the active demand for the product versus the limited amount of supply.

Coal Tar Sealers

Coal tar is the most popular asphalt sealer in the market as it is weather-resistant and provides a long-lasting shiny finishing.  Like its namesake suggests, coal tar sealers contain a substantial amount of coal tar mixed in with other polymers and strengthening additives. This water-based sealant is manufactured by baking coal. Coke is then extracted from the baking process which then becomes the main component of coal tar sealers and is the reason why it is resistant to petroleum-based chemicals.

Unfortunately, coal tar sealers are also believed to have a long term detrimental impact on the health of local occupants as well as harm the environment. In June 2011, the Suffolk County Legislature have joined the states of Texas and Minnesota in officially approved a permanent ban on the sale of coal tar sealers as the sealer is believed to be contributing to water pollution and emits a harmful carcinogenic compound known as polycyclic aromatic hydrocarbon. As at this point of writing, companies such as Home Depot and Lowe’s have also halted the sale of coal tar sealers due to the potential liability.

Fast Dry Sealers

Fast dry sealers are meant to patch up roads with high traffic, such as parking lots and major roads leading to public areas such as gas stations and hospitals. The best thing about using fast dry sealers is that it curates in less than an hour, thanks to the additional geo-textile fibers added into the sealant. However, this also means that fast dry sealers are much costlier compared to other types of asphalt sealers. Purchasing this sealer type in small quantities will also prove challenging as most manufacturers of fast dry sealers deal directly with road works companies. When you do eventually find a source distributing this sealer type, you might want to buy in bulk and share the costs with your neighbours. Due to the high cost of material, you might also want to apply fast dry sealers on critically cracked areas on your pavement, followed by a cheaper type of asphalt sealer.

Acrylic Sealers

Another expensive type of asphalt sealer is known as acrylic sealers, which is the epitome of what the perfect asphalt sealer should be. Acrylic sealers are easily identifiable due to its varying degrees of colour, as it can be shaded in black, red, green or clear colouring. These sealers are typically applied onto outdoor tennis and basketball courts as well as shopping mall parking lots. Acrylic sealers are UV resistant, highly durable and impervious to harsh environmental conditions.

Acrylic sealers also do not contain any petroleum by products, which means that it is environmentally friendly as well. Another great benefit of this sealer is that it only has to be reapplied every seven years as well, thereby contributing to savings in terms of maintenance costs.

Defining Quality Sealers

While it would be tempting to plainly opt for the highest quality sealer with the equally high price tag, a better way of selecting the appropriate asphalt sealer for your own use would be to simply look at the warranty duration. Generally, anything with a five to six year warranty would be a safe bet. If you have an ample budget, you might also want to consider opting for a sealer with additional acrylic polymers thrown in as well, as some of these products come with an impressive seven to ten year warranty.

In terms of pricing, asphalt sealers tend to command higher pricing as it is environmentally safer and lasts longer as well. Although it is possible to get a 5-gallon pail of asphalt-based coating for less than USD10, do keep in mind that this layering will probably only last for one season. On the other hand, a decent quality asphalt sealer should cost you anywhere between USD12 to USD15 with a coverage ranging from 250 to 350 square feet. Regardless of whichever type of asphalt sealer you choose, one thing for sure is that the total cost of maintaining the driveway on your own will save you up to 65% of the cost for professional maintenance.

DIY Asphalt Sealing Advice

If you intend to repair and maintain your own driveway, then you should do your due diligence and take some time to study the instructions on how you can prep the asphalt sealer before application. Some asphalt sealers can be directly applied on to the pathway whereas others may require thinning, special handling or curing before application. When in doubt, it is always best to first seek professional advice before starting on your project.

Asphalt (also known as bitumen in some countries) is easily identified due to its black and sticky texture. Before it is extracted from crude petroleum or natural deposits, asphalt is also known as pitch. This highly viscous liquid is mainly used in road construction and waterproofing of roofing, as its gluey attributes make it the ideal material to bond aggregate particles together. The final mixture of asphalt combined with aggregate is hence known as asphalt concrete.

What is Recycled Asphalt?

In technical terms, the Western United States defines virgin asphalt as a “bituminous substance that is used to bind aggregate together to create asphalt concrete.” Generally, asphalt concrete consists mainly of aggregate in which asphalt only makes up 5 to 7% of the total composition.

Recycled asphalt on the other hand is quite simply asphalt concrete which has been reprocessed by mixing the reclaimed asphalt pavement with new asphalt and aggregates. In some circumstances, a recycling agent is also introduced into the mix to improve the performance of the recycled asphalt by softening and rejuvenating its mechanical properties.

The process of creating recycled asphalt usually begins with cold planing (also known as cold milling). In this procedure, the top layer of the pavement is removed using a cold planning machine. The pavement is usually made from Portland cement concrete which can then be crushed and used as the aggregate to form the recycled asphalt. After the recycled asphalt has been mixed, the composition can then be used to overlay the exposed pavement, thereby completing the recycling process.

Other types of asphalt recycling are known as hot recycling, hot in-place recycling, hot mix-remixing, hot mix-repaving, hot mix-heater scarification and full depth reclamation.

Why Recycle Asphalt?

Despite its elaborate process, recycling asphalt can help local governments save money from having to pave roads with new materials. At the same time, the act of recycling also introduces new business opportunities and will help create a greener environment in the long run as well. In 1990, the California Integrated Waste Management Board concluded that Construction and Demolition materials (including asphalt) made up 28% of the waste stream, totalling up to 11 million tons of waste in that year alone. A much deeper studied discovered that out of the 11 million tons of waste, 8.2 million tons were found to consist of asphalt, dirt, concrete, brick and other rubbles, out of which only 57% was recycled.

As asphalt also contains a high amount of oil, the price of virgin asphalt has also dramatically increased in line with the drastic oil price hike. With oil prices now hovering around the USD90 range, the demand for recycled asphalt is also growing in tandem as recycled asphalt is cheaper and yet just as durable as virgin asphalt.

Even if costing is not a problem, we are all obliged to protect the Earth’s natural resources for the sake of sustaining future generations. The repeated creation of asphalt is also known to contribute to environmental pollution, which is why recycling such toxic material is an effective method of reducing toxin production around the globe.

The creation of materials such as asphalt is also believed to contribute to climate change problems due to the burning of fossil fuels during the creation of asphalt. In contrast, producing recycled asphalt does not require any form of fossil fuel to be burnt, thereby preserving on our natural resources while also decreasing air pollution.

Roads paved with virgin asphalt have also been blamed for the urban heat island effect, which is a phenomenon where heat from the sun is absorbed into the ground, thereby heating the paved area even after the sun has set. On the other hand, recycled asphalt is lighter coloured, thereby making it less susceptible to heat absorption from solar radiation and hence, contributes less to the urban heat island effect.

At the same time, the introduction of recycled asphalt into the market can not only meet the USD100 billion asphalt demand but can also help create job opportunities as more recycling asphalt plants are created. As Asian countries in particular began to increase the amount of roadwork constructions, the recycled asphalt industry becomes a blue ocean choice in a red sea filled with expensive virgin asphalt suppliers whose prices are closely dependent on the price of oil at that point of time.

How to Fill Gaps with Recycled Asphalt

Homeowners can also contribute to a greener environment by applying recycled asphalt along their driveways as well. The first thing you need to do is thoroughly clean the surface of your pavement. It is best to do this with a high powered air blower first followed by a high power washer. You might also want to do this on a sunny day as it is important to allow the surface of your pavement time to completely dry before proceeding to the next step.

While waiting for the surface to dry, carefully mix hot or cold crack fillers. You can then fill up the holes in your driveway with the crack fillers, followed by a generous shovelling of recycled asphalt. To achieve a smooth finish, do run an asphalt rake over the surface area. To further condense the gap and prevent further cracks, you might also want to run a vibrating plate (or hand tamper) over the filled surface as well.

Next, carefully corner off the area to allow the filled gaps to completely dry for at least 24 hours before proceeding to apply commercial-grade asphalt seal coat to the surface. The purpose of the seal coat is to protect and extend the lifespan of the newly applied recycled asphalt, so do not skip this step.

How to Create Pavements with Recycled Asphalt

If you’re creating a new pavement, you might want to consider surfacing your pathway with recycled asphalt as well. A depth of at least 3 inches should first be created virgin aggregate is added, followed by recycled asphalt. Although recycled asphalt tends to leave tracks due to the higher content of oil, line paint and rubber, an extra layering of asphalt sealant can easily protect the rest of your flooring from asphalt contamination. Generally, we recommend that the sealant should at least be 1 inch thick to protect the integrity of the newly installed asphalt pavement.