Asphalt Sealant: Oil-based or Water-based?

A tire track on asphalt.
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  • Beginner

Applying asphalt sealant is important to prolonging the look of your asphalt driveway or if you are working on projects like major highways.

Different weather conditions can cause asphalt to crack and crumble—the sun’s heat can cause the asphalt to oxidize, and during the winter months, cold temperatures can damage it due to freezing water.

Even rainwater can cause problems, which is why it is so important to use sealant to maintain the structure of the asphalt.

Sealant can be bought in bulk or in quantities just enough to repair or seal your driveway, but what type do you use? There are two main types—oil-based and water-based.

Both have their benefits but you must choose what is right based on your needs.

The Basics About Oil and Water-based Sealers

installed an asphalt driveway

Oil or asphalt-based sealers have the quality of putting components back into your asphalt that are lost due to everyday exposure to ultraviolet rays and weather, such as rain and snow.

Asphalt itself is actually a byproduct left over when oil has been refined to gasoline.

These types of sealers have additives that increase resistance to gas leaks or oil spills from vehicles because unsealed asphalt will eventually be dissolved by these compounds.

Other additives such as coal tar and polymers are also added to this type.

Coal, tar-based, or water-based asphalt sealers may contain latex, polymers, and clay. They are similar to oil-based sealers, but they’re known to be more resistant to oil and gas spills when compared directly.

This is why water-based sealant is the kind used on major highways and freeways.

Such big roads have heavy traffic that will often suffer from gas or oil leaks and water-based asphalt sealants can help prevent early damage and ensure maintenance is not required for at least five years.


oil spot on an asphalt surface

The main difference between these substances is in the appearance.

Because oil-based sealants must have additional mixed polymers to be able to keep them durable when exposed to vehicle fluids, they’re harder to clean up and have a duller look.

Water-based types will actually stay on top of the asphalt instead of penetrating it, creating a smoother finish than the oil-based variety.

In essence, one must choose a type of sealant that will have more solids left over when the solvents have evaporated and cured.

This is one way you can tell the product is high in quality. Also take into consideration the length of warranty on your sealant. Five years or so is ideal so you can be sure your driveway is protected.