What is Tar and Chip Seal?
Tar and chip sealing is a paving method that combines asphalt and stone to create a durable and textured surface. It's often described as a "country cousin" to solid asphalt. The process typically involves:
- Gravel Base: A gravel base is installed.
- Liquid Asphalt Application: Hot liquid asphalt (tar) is applied over the gravel base.
- Stone Chip Spreading: Selected stone chips (aggregate) are spread over the hot tar. These can come in various colors like brown or gray for decorative purposes.
- Compaction: The stones are then firmly rolled and compacted into the hot tar, embedding about two-thirds of the gravel into the asphalt, with the tops of the stone chips sticking out to create a textured finish.
- Curing and Sweeping: The surface requires a curing period (up to two days) during which the remaining water in the emulsion evaporates and the asphalt hardens. After curing, any loose gravel is swept off.
Benefits of Tar and Chip Seal
- Cost-Effective: It is generally much lower in cost to install than concrete or traditional asphalt paving, making it an economical option for driveways and roads.
- Low Maintenance: Tar and chip surfaces are relatively maintenance-free. Unlike asphalt, they typically do not require repeated sealing, and small cracks may self-heal.
- Excellent Traction: The rough, textured surface provides superior grip for feet and tires, especially in wet or snowy weather, enhancing safety.
- Durability: Tar and chip driveways are very durable and can last for many years, often longer than an "equivalent" blacktop drive. They protect the underlying pavement from oxidation, aging, and traffic wear.
- Aesthetic Appeal: It offers a distinct "rustic country" look or a designer stone finish, providing a decorative alternative to a plain black driveway.
- Seals Cracks and Imperfections: It effectively seals cracks and minor imperfections in existing pavement, extending its life.
- Quick Installation: Compared to other paving methods, tar and chip seal paving can be installed relatively quickly.
Comparison to Asphalt
Tar and chip driveways are similar to standard blacktop in composition, as both use asphalt cement for adhesion. However, blacktop is mixed at a central plant with completely coated aggregate, whereas tar and chip surfaces involve applying liquid asphalt and then spreading clean, angular, similarly sized stone chips on top at the site. This process results in a surface that looks like stone but performs like asphalt.