What is Asphalt Sealant?

Asphalt sealant is an effective solution for protecting asphalt surfaces, such as parking areas, streets, and for the homeowner, driveways.

A mix of sun, moisture, and temperature can lead a driveway to expand, contract, and pull apart. Yet a simple sealant can help it withstand such punishment. When considering this investment, think curb appeal and your home’s overall value.

Yes, It’s Sealant – But It Looks Great

Looking at your driveway, you may think that it looks perfectly fine. However, it’s not about the here and now. Just like car maintenance, action isn’t taken for what has happened, but what could happen. In the case of an asphalt driveway, this generally means costly repairs.

Keep in mind that asphalt is a flexible product. Once laid down, it will indeed change according to its environment. For example, ultraviolet rays from the sun will dry out asphalt, causing the surface to gray and for tiny alligator cracks to appear. If not addressed, these seemingly harmless cracks can turn into troublesome potholes.

Coal Tar or Asphalt-Based Sealant

Applying asphalt sealant can be done by yourself or by a professional. Note that there are two types of sealants to choose from: coal tar or asphalt-based.

All driveway sealers are water-based emulsions containing water, latex, polymers, clay fillers, and additives. You can then choose between sealants made from coal tar or asphalt. While the latter is more environmentally friendly, the former is known for its durability, oil-resistance, and affordable cost. As a result, coal tar sealants remain the more popular choice.

Another consideration is plain vs. filled sealers. In the latter’s case, the sealer contains sand, perfect for filling in cracks and holes. However, depending on the condition of your driveway when you seal it, a filled sealer may not be necessary.

FAQs About Asphalt Sealant

How often should you seal your driveway?

Manufacturers recommend resealing a driveway once every two or three years. If you’re doing in yourself, you can save up to 65%. Be sure to review the entire project before taking it on though. As with anything DIY, you want to do it right the first time. Mistakes can turn costly in a hurry.

How do the elements affect asphalt sealers?

Driveways help beautify the home, creating a natural extension from the road to your garage. It’s curb appeal at its most basic. It’s also an investment that needs protection — from being driven on, a game of basketball, and most of all, from the elements.

Ice, snow, heat, and rain all have an impact on asphalt. From heat that swells the surface to the winter cold that contracts it, asphalt has a tendency to “crack” under such pressures. Once the oxidation process begins, it’s not easy to reverse. However, it can be halted. A sealant can help it better absorb such fluctuations.

While sealing the driveway is a good idea for all homeowners, for those who live in areas of extreme weather (such as the south, northeast, or desert areas), it’s a must. Indeed, asphalt sealant is the perfect example of a small investment today that should yield considerable savings in the future.

Strange to think, but the asphalt paving that will go on your sweet little old driveway is the same stuff that road crews put down. While you can’t expect a team of orange-vested workers to bring in exactly the same machines that are used on roads, the mixture–called “hot mix asphalt paving”–is really the same thing.

It’s an aggregate of stones and sand mixed in with liquid asphalt. The reason it’s called “hot mix” is because it’s heated to over 300 degrees Fahrenheit, and it’s the intense heat that liquifies the asphalt.

The hot-mix asphalt may be laid on top of your existing driveway. If the driveway is not in good shape, it is removed and the new hot-mix asphalt is laid on top of a base of several inches of aggregate or laid directly on top of soil.

The hot mix is delivered to your house in a hot, soft, ready state. As the mixture cools, it hardens.

Read on, though, to find out why full-depth is preferable to the overlay method.

Overlay Asphalt Paving

If you have an existing asphalt or concrete driveway, but it’s in poor repair, you can overlay another layer of asphalt paving on top.

Still, the existing surface needs to be in a minimally good condition to support the new asphalt paving. If more than 75% of the existing driveway is cracked, you’re better off pulling off the driveway and starting anew.

The asphalt contractor will first patch minor holes and cracks with hot mix. Then a surface of up to 2 inches of hot mix will be laid on top of the patched driveway.

Full-Depth Asphalt Paving

Full-depth is the better option. There are two ways to define full-depth asphalt paving.

Actual Full-Depth.

Nothing between the hot-mix and the soil. Four to six inches of hot-mix asphalt laid directly on soil. This is the most preferable type of full-depth paving.

Full-Depth With Partial Aggregate Replacement

Three inches of compacted aggregate base is equal to one inch of hot-mix asphalt paving. A typical arrangement is to lay down 6-8 inches of compacted aggregate under 3 inches of hot-mix asphalt paving.

• Asphalt paving is more flexible–and therefore less prone to cracking–than concrete.
• Asphalt paving is done by the hot-mix method and therefore sets faster than concrete, which needs to dry.
• Asphalt paving is unaffected by the application of rock salt or ice melt during winter months.
• Asphalt paving is generally cheaper than concrete paving.
• Asphalt paving does not need the installation of rebar forms. It can even be installed over an existing driveway.
• Asphalt paving is a competitive business, so it is possible to find good deals.

Q:  Can I use a driveway sealer like MasterSeal instead of the more expensive option of an entire new hot-mix asphalt driveway?

Yes, you certainly can–if your driveway is in good enough shape. Driveway sealers are only a surface treatment, though–a way to extend the life of your driveway. It’s the driveway equivalent of painting your house.

Q: What about crack sealing instead of using driveway sealer?

Crack sealing is a more effective type of patch than driveway sealing alone. You’ve seen this before on roadways: this thick, caulk-like substance injected in cracks. Crack sealing can definitely extend the life of your driveway more than driveway sealant, but not as well as an entirely new hot-mix asphalt paved driveway.

Q: I’ve decided that my asphalt driveway is in such bad shape that I can’t use driveway sealer. What’s the cheapest way to install real hot-mix asphalt?

Yes, you don’t need to rip out your existing driveway. If your existing driveway is in decent enough condition to provide a solid base, you can use the overlay asphalt installation method.

Q: Does weather affect when I can install asphalt paving?

Yes. Warmer temperatures give the contractor more time to work with the asphalt before it hardens. For 1 1/2″ of asphalt paving, temperatures should be at least 70 degrees Fahrenheit. Two inches of asphalt paving give you a wider range of temperatures to work with–40 degrees is the minimum. Wind conditions will decrease the amount of time the contractor has to work with the asphalt. If there is too much moisture, paving may be delayed until conditions are dry.