What is tar and chip paving?
Tar and chip paving, also referred to as chip sealing, is very similar to asphalt. It is a combination of hot liquid asphalt cement (liquid A/C or hot tar) as a binder and gravel as the main structural component. Unlike asphalt, which is premixed at an asphalt plant, the components of tar and chip are delivered separately and mixed on the jobsite. Tar and chip is nothing new. It has been used for over 100 years, all over the world with great success, to pave and resurface roads, parking lots, residential driveways, and more. Tar and chip is used by county and DOT road crews on road paving projects in virtually every state in the United States.
How is tar and chip installed?
The prep work for tar and chip is almost identical to asphalt paving. After the prep is complete, a coat of liquid A/C is applied to the existing surface by using a computer controlled distributor truck equipped with spray bars. The spray bars apply an exact and consistent amount of liquid A/C, heated to the right temperature. Next, a clean crushed chip stone is spread using a spreader box attached to the dump truck transporting the gravel. The stone adheres to the hot liquid asphalt. Finally, a roller is used to embed the stone into the tar. The entire process is repeated on jobs where multiple courses are required.
How long does tar and chip last?
This is a very difficult question to answer because it depends on two factors.
- Perspective: To some people, a paving job would need to be redone as soon as it gets a worn spot or broken edge, while others will be perfectly content dodging potholes for many years, as long as they have a clean paved surface for vehicle traffic.
- Job site/usage:Durability can vary based on several factors, such as climate, traffic conditions, base, and the number of courses of chip seal used. Naturally asphalt or tar and chip will last much longer on a low traffic, residential driveway than on a county road or city street.
Let’s assume we are talking about the point where a paved surface is in bad enough condition that repairs are no longer a viable option. Traffic conditions are pretty typical at that site. The life expectancy for an asphalt paving job is probably around 12 years and, in that time, repairs such as patchwork, crack sealing, and seal coating will be required. For tar and chip, probably around eight years, with patching and isolated re-tar and chipping will be required during that time. Typically, tar and chip paving will last about two-thirds as long as asphalt paving would.
Why use tar and chip instead of asphalt?
- Natural beauty:Tar & chip, provides a beautiful rustic alternative to asphalt, with the look and feel of a country gravel road.
- Cost effective:The initial cost of installing tar & chip, can be up to 40% less than a comparable asphalt installation.
- Maintenance free:Unlike asphalt, which requires seal coating every few years, tar and chip is virtually maintenance free, as there is never a need to sealcoat.
- Improved traction:The rough, gritty surface of tar and chip gives great traction, even in wet weather, and is an excellent choice for steep slopes.
- Cooler temperature: Because of its light colored stone surface, chip seal does not absorb heat like blacktop does, staying much cooler.
- More convenient: Tar and chip goes down faster than asphalt and there is hardly any down time because it can be driven on immediately. You do not need to wait 24 to 48 hours for it to harden like asphalt.