Asphalt Paving Sealer: Saving the Driveway Track from Cracking

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Asphalt Paving Sealer: Saving the Driveway Track from Cracking

Asphalt sealers protect asphalt paving on driveways against the deleterious effects of air, sunlight, water and ice, which can lead to cracks.

Asphalt, which is also called blacktop, apart from being aesthetically pleasing and durable, is a very interesting material used for paving driveways. The material is actually marketed by the asphalt industry as a pliable pavement. This is based on the fact that the asphalt cement, which is the material that binds together the sand and small bits of stone, remains malleable for a long length of time. This attribute makes the blacktop or asphalt resistant to cracks if it is installed properly.

How Asphalt Driveways Begin Developing Cracks

When asphalt is exposed to sunlight and air beyond a certain period of time, it starts losing its malleability. The asphalt then actually starts oxidizing. The sun’s ultraviolet rays also cause the asphalt cement to breakdown. This is when problems start occurring.

Once the asphalt begins oxidizing, it starts getting brittle. The binding effect between the asphalt and the stone particles and sand, also known as aggregate, starts to come apart. Which results in the individual parts of the aggregate loosening, leading to cracking. In places where the climate is cold, there is an acceleration of this process when water gets into these cracks and gets frozen.

How Asphalt Sealers Protect Asphalt Driveways From Cracking

Applying an asphalt sealer on your asphalt driveway, will not only increase its aesthetic appeal but will also make it more long lasting. Asphalt sealers act as a protective shield on asphalt paving, preventing sunlight and air causing damage to the asphalt cement. It also protects the paving from the ultraviolet rays from the sun. An asphalt sealer will also prevent ice and water seeping into the asphalt causing it to disintegrate.

There Are Various Types Of Asphalt Sealers

Traditional Asphalt Sealers: The traditional type of asphalt sealers consist mainly of the same asphalt used in the paving itself. The asphalt in this type of sealer is usually mixed with an emulsifier, which is a soapy compound, and water. The lifespan of this sealer is the shortest and it hardly offers any protection against the sun’s ultraviolet rays.

Coal Tar Asphalt Sealers: The next type of asphalt paving sealer consists of refined coal tar. This type of sealer is very effective against oil and gasoline. Motor oil and gasoline actually have the effect of dissolving the asphalt cement in the paving. These coal tar sealers also have an emulsifier and small particles of clay, which help in applying it easily. Some of them are also modified with polymers, which provide longer life, a richer color, and extra protection against ultraviolet rays.

Acrylic Polymer Asphalt Sealers: These asphalt sealers are the most expensive and are completely synthetic. These sealers are usually the ones seen on tennis courts. Manufacturers make it in black to be used on driveways. These asphalt sealers provide the most effective overall protection and usually last twice as long compared to other sealers.

These sealers usually come with sand. As far as asphalt sealing is concerned, sand is a very beneficial ingredient. It seals the pores on the asphalt paving, improves car and foot traction, and also increases the life of the asphalt sealant on your driveway.

The Frequency Of Applying Asphalt Sealing

According to the manufacturers of asphalt sealers, once new asphalt is laid, it should be allowed to cure for around a year, after which it should be given a protective coat of asphalt sealant.

Most homeowners make the mistake of using asphalt sealing on their driveway too frequently, as in every year. The disadvantage of sealing too often is that it can lead to a build up of the sealer, eventually resulting in peeling, so that it can also get tracked indoors. Vinyl flooring, for instance, can be stained permanently by asphalt sealers, even if it is removed promptly.

The manufacturers of asphalt sealers as well as asphalt contractors advise that sealing every three years is quite adequate for most asphalt driveways, except in regions where the conditions are exceptionally harsh, as in desert areas.

A good rule of thumb is not to apply a new coat until the previous coat of sealant has worn off, which will happen at various rates, according to the volume of traffic and of course the exposure to weather conditions and sunlight.

Another indication of it being time to apply a new coat of sealant is when the asphalt begins graying, which is indicative of the oxidization of the surface, resulting in the loosening of the binder that binds the aggregate.

By Rita Putatunda
Published: 12/3/2007

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