Road Sealing 101: How Do You Seal a Road?

Road Sealing 101 How Do You Seal a Road

The importance of sealing a road correctly cannot be understated

Road Sealing is a resurfacing technique wherein a particular mixture is applied to the roads to protect them from wear and tear. Roads must be well-maintained and sealed to ensure ease of travel from one point to another. Both Australia and New Zealand enjoy vast land areas, which is why the two countries’ road system plays an integral role in their development.

What are the advantages of sealing a road?

Economics – having sealed roads reduces road abrasion, eliminating the need for constant repairs, and disruption of everyday traffic is also avoided, saving time intended for productive work activities.

Dust suppression – this is true for most rural areas. Sealing gravel roads is the best way to rid of dust, especially during the summer season when the roads are dustier.

Ease of access during wet weather – unsealed roads can inconvenience motorists during the rainy season, especially if the roads are unsealed. Mud build-up is imminent, and this can affect the ability of roads to be available for traffic 

More comfortable ride for motorists – unsealed roads are prone to damage. Potholes and cracks can bring a level of inconvenience to motorists.

What are the common materials or treatments used in road sealing

What are the common materials or treatments used in road sealing?

Chipseal – Chip seal or tar and chip is one of Australia’s most common pavement surface treatments. Chipseals are asphalt overlays combined with aggregates such as gravel, sand, or crushed rocks. It is relatively cheaper than asphalt concrete but not as enduring.

Tarmac – short for “Tarmacadam”, this type of road sealing treatment is more dust-free and lasting. It is made out of combining sand, crushed stone, and tar. 

Asphalt Concrete – since the beginning of the 20th century, asphalt concrete has been used to construct pavement. Today, it is most commonly used on roads and even dams. This material is made from mineral aggregates bound by asphalt.

Bitumen – is also known as asphalt. Its primary use is in road construction and is characterised as black and sticky.

How do you prepare a road for sealing

How do you prepare a road for sealing?

  1. The existing pavement or base course is prepared accordingly before sealing. First, the unsealed pavement is swept to remove the fine layer that can affect the adhesion of the sealing binder. Dust is the major impediment in asphalt adhesion. If necessary, construction firms can use water flushing to carry out this job.
  2. Pavement construction technicians can do digging and patching in areas with oil drip or spillage. Some of them use oil spot primers to remedy the area.
  3. Surface repair should be carried out regardless of whether the road will be sealed for the first time or just being resealed. Potholes, cracks, and other structural defects can be patched and given sufficient time to settle.
  4. If edge breaks are present on prior sealed roads, carry out repairs by re-establishing the width of the pavement.
  5. Trenching or digging surface drainage should be avoided as it can affect the seal’s life.

After preparation, how do you seal a road?

  • The process begins with the application of the road seal mixture. Asphalt is often combined with water which evaporates almost instantly.
  • Gravel or cracked stones are spread over the surface to prevent excess water from entering the shell and softening the road.
  • Gravel is embedded into the mixture by high-pressure rollers. Some instances require sand to help the binding and curing process.
  • Curing can last for a couple of days, but hot weather can speed the process. Both vehicle and foot traffic can use the road at this stage but at a controlled speed.
  • Excess gravel is then eliminated through repeated sweeping. 

How often should a road be re-sealed?

Now that the road has been sealed, an important thing to consider is the frequency of resealing. Although there is no definite answer to how often a road should be resealed, the ideal time frame is 3 to 5 years. It is vital to note essential factors that can affect the treatment.

What factors can affect the life of a sealed road?

Usage – traffic can affect the existence of a sealed road. Therefore, questions like, “Is it catering to heavy vehicles?” and “Is it subject to consistent use?” should be considered.

Climate – the Australian climate can be severe. If the sealed road is subject to extreme temperatures, resealing will be done more often than usual.

What are the common problems that sealed roads experience

What are the common problems that sealed roads experience?

Having a road sealed does not necessarily guarantee a permanently smooth-sailing ride. There could also be instances of failed sealing. The problems mentioned below are termed “Sealed Road Failure Modes”. They occur because of substandard materials used in road sealing. Similarly, if work is rushed, it compromises the quality of the output:

Flushing – also known as bleeding, flushing happens when the aggregate submerges into the binder. This is caused by not having enough air voids in the seal to contain the bitumen and aggregates.

Rutting – these are vertical deformation in pavements caused by the passage of heavy vehicles. Additionally, wheel ruts can hold water during the rainy season. They can cause more extensive and more progressive problems on the road.

Cracking – cracks can be measured in two ways:

  • ‘Cracking Severity’ pertains to the width of the gap. It has a numerical value.
  • ‘Cracking Extent’ is the percentage of the cracked road surface.

Edge Break – The edge of the pavement is bound to break when it is not strong enough. This also happens when water enters the pavement through the shoulder.

Potholes – just as the term suggests, a pothole is circular road damage caused by the combination of excessive water during construction and traffic.

Stripping – stripping ensues when the surface of the road losses aggregates and reveals the pavement or the binding material used.

Ravelling – ravelling usually transpires when both binder and aggregates disintegrate because of excessive exposure to water and heavy traffic.

Contact Road Seal Australia, the experts in road construction and surfacing solutions

Contact Road Seal Australia, the experts in road construction and surfacing solutions

If you are looking for high-quality asphalt and bitumen road sealing services, call Road Seal Australia on 1800 902 202 or email your enquiries to For years, we have been providing our services to tens of residential, commercial, industrial and government clients in Australia’s east coast and we are ready to help you.