Chipseals are constructed by evenly distributing a thin base of hot bitumen or asphalt onto an existing pavement and then embedding finely graded aggregate into it. The aggregate is evenly distributed over the seal spray, then rolled into a smooth pavement surface. A chip-seal-surfaced pavement can optionally be sealed with a top layer, which is referred to as a fog seal or enrichment.
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Although chipseal is an effective low-cost way to repair road, it has some drawbacks. Loose crushed stone is often left on the surface, owing to underapplication of bitumen or overapplication of stone. If not removed, this can cause safety and environmental problems such as cracked windshields, chipped paint, loss-of-control crashes (especially for motorcyclists, bicyclists and small trucks), and deposition of foreign material into drainage courses. Therefore, it is very important to sweep the road after the emulsion sets. As mentioned earlier,this problem can be minimized by using chips precoated with bitumen. Overapplication of emulsion can lead to bleeding, a condition where the excess asphalt rises to the surface, creating a very smooth surface that is very slippery when wet and bubbling in the hotter summer months. As cars drive over it the tires kick up this tarry substance on to the side of the car. It can only be cleaned off with a solvent remover or diesel fuel.