Chipseal Season is Upon Us

As we approach the warmer months, chipsealing on our roads across New Zealand gets into full swing!

We share with you what chipsealing is, why and when chipsealing happens in New Zealand and tell you what you should be aware of when driving through chipsealing in progress.

What is Chipseal?

Chipseal is made of sprayed hot bitumen, or bitumen that’s sprayed on cold, (bitumen emulsion) with crushed stone (small, sharp-edged rocks) known as ‘chips’ rolled into the surface.  Interestingly, there are differences in the chipseal used in the North Island versus the South Island, in regard to where the material comes from; in the North Island material comes mainly from quarries, whereas in the South Island, from rivers. The colour is also different; in the North Island it’s darker due to the use of pure volcanic materials, whereas in the South Island the chipseal is more grey than black.

Waka Kotahi NZ Transport Agency describes chipseal as “the most common type of road surface in New Zealand. Economical, flexible and hardwearing, it provides an adaptable, cost-effective and safe surface for road users. We regularly monitor all chipseal surfaces to make sure they continue to perform at their best”. 

Why and When Chipseal is Used

In New Zealand, there are a number of reasons and situations chipseal is used, including:

  • To improve road safety through improving the surface grip which ultimately reduces the time taken to stop when braking in an emergency
  • To improve the waterproofing abilities of the road surface
  • To extend the life of the road and
  • To provide value for money in regard to maintenance spend.

Chipseal is predominantly used on state highways that are usually outside the main urban areas whose roads have lower traffic volumes.

You might have wondered, and even cursed out loud while driving, why are they chipsealing in the peak of summer when the roads appear busy with holiday makers! There is a good reason for this and it’s not to intentionally frustrate drivers.

Bitumen is a liquid when it’s hot and hard when it’s cold, so summer is the best time to reseal roads as for chipsealing to work correctly it needs warm temperature and dry air. These conditions ensure the new seal sticks properly and will enable it to become strong and long lasting.  Cold weather on the other hand, can make it crack and wet conditions mean the bond between the bitumen and the road, fails.

Also, while the summer holidays might have a few peak days of traffic on the road, a great number of New Zealanders take time of work in January. This means carrying out chipsealing during this time, actually reduces any peak time traffic jams that could happen if it was carried out when most people are driving to and from work.

What to Be Aware of When Driving Through Chipsealing in Progress

It’s important that when you drive through any roadworks where chipsealing is taking place that you reduce your speed and follow the speed signs throughout the roadworks area. It’s important to drive slowly as sealing chips are often flicked up from the road surface.

Once you’re at your destination, we recommend you wash your vehicle as hot bitumen can splash up and stick to your paintwork.  Also, it’s a good idea to check your brakes afterwards to make sure no loose stones have been lodged.

Chipsealing is a common practice throughout New Zealand over the summer months to maintain our roads and make sure the roads are performing to their optimum. While it may appear an inconvenience for your travel over the holidays, this work is beneficial and has an ultimate goal to keep those traveling on state highways safe!