Asphalt seal coating is important because although asphalt has great waterproofing and adhesive properties, it also has some rather serious flaws that relate to its chemical makeup which provides easy access to weather, salts, and chemicals that destroy the asphalt molecules. As these molecules are destroyed, asphalt will lose much of its original properties, such as waterproofing and binding. The first visual sign of this is a change in color from black to brown to gray. As asphalt is a byproduct of petroleum distillation processes, it is easily dissolved by the many other products that are also derived from petroleum. This is because these individual items come from the same source, and therefore have a natural affinity for each other and will try to rejoin when put together again. Therefore, oil and gasoline both work to easily dissolve asphalt, which contains many very similar chemicals.Have a look at Hanover Seal Coating for more info on this.
This problem is normally only seen in off-street, low traffic pavements such as driveways or minor streets; places where the oil and gasoline have a chance to sit and soak in. Asphalt seal coating can resist these other substances and keep these chemicals from interacting, therefore extending the life of the asphalt and preventing the need for excessive, expensive repairs and patching. If your asphalt does need to be repaired, however, be sure to do it quickly as no seal coating can protect the asphalt from water and other elements once the surface itself is cracked. Although once a crack appears, they do tend to come back, it’s still worth it to patch and fill them as it’s much cheaper to do this than to re-lay an entire driveway or parking lot.
Contrary to popular belief, however, your asphalt does not need to be re-coated yearly. Re-coating too often can actually cause problems, such as peeling at around the ten year mark. You should also be very, very careful with who you choose to lay your asphalt seal coating. As consumers in generally are not very educated about the process, many unscrupulous types are taking advantage of them. Common practices include diluting the sealant to the point of being completely ineffective. Be sure that whoever you hire is local, in your phone book, and happy to show you his insurance certificates. If they’re from out of state, it’s probably safer to just turn them away. After all, who are you going to call if something goes wrong?