Chip Seal Installation Process

First, the road surface is prepared.

The road is swept to provide a clean surface. Manhole and utility covers and site-specific things like ornamental crosswalks are marked and covered. Prior to the chip seal crew arriving, asphalt failures will have been patched. Large cracks may also have been filled. Utility adjustments may have been made, however, they are generally unnecessary with chip seals as the completed overlay is well under an inch.

Next, asphalt binder is applied to the road surface.

A distributor applies a hot liquid asphalt or an asphalt emulsion onto one lane of the road at predetermined rates. This layer seals cracks and acts as a binder for the layer of crushed aggregate.

Then, stone aggregate is applied to the asphalt binder.

A chip spreader evenly drops crushed stone aggregate onto the lane of fresh liquid asphalt. A gauge determines the rate at which the chips fall to ensure the desired amount of chips are applied to the road. The chip spreader is often mated to a dump truck which feeds the aggregate to the spreader.

The layer of chips is then rolled into the asphalt binder.

A standard drum roller, a rubber tired roller, or a combination of the two, roll the entire surface to embed the aggregate chips into the liquid asphalt.

Finally, the process is repeated with smaller chips.

A second pass is made by the asphalt distributor to apply another layer of liquid asphalt. A second layer of smaller aggregate or sand is then applied. The second layer of smaller material helps to lock in the larger chips on the bottom and produces a smoother riding surface.

Please note that the process described is for the most common form of chip seal we produce. The process will vary for other variations of single, double and triple seals.

The first step is to apply some type of chip seal.

For a Cape Seal, a double layer of stone is not always necessary since the surface will be covered with an asphalt slurry surfacing. In some cases, a second lighter pass of liquid asphalt followed by a layer of sand is applied to help fill voids,  keep the asphalt binder from bleeding to the surface and give the new surface additional strength.

Next, the surface is swept to remove any loose material.

Not all of the material placed during the chip seal process will be embedded in the asphalt binder. Therefore, after the chip seal has had time to cure, the surface is swept to create a clean, sound surface for the top layer of slurry seal or micro surfacing to adhere to.

Lastly, a slurry seal or micro surfacing is placed.

The slurry seal or micro surfacing is applied over the chip seal to further lock in the chips and provide a darker, smoother riding surface. Cape seals perform much like a thin lift overlay but can be produced at a substantially lower cost.

A specialized attachment scrubs in the liquid asphalt.

The scrub seal production process is very similar to a traditional chip seal. The main difference is that the distributor is fitted with a specialized piece of equipment with stiff brushes that "scrub" the liquid asphalt into the road. The liquid asphalt is also placed at slightly higher rates in order to best fill cracks and voids prior to the chips or sand being placed.