Bitumen/asphalt driveways


What is an asphalt driveway? 

Asphalt is made of a mix of asphalt (a dark bituminous pitch) with aggregate (stone, sand and gravel). The mix is usually 5% asphalt and 95% aggregate. It’s widely used for driveways, car parks, and roads. 

The substance is also referred to as bitumen. 

What’s the best use? 

Asphalt is suitable for a wide range of driveways, as it is very versatile. 

What maintenance is required? 

A clean once or twice a year with a broom and power washer and the application of a seal coating every two to five years. 

What are the minimum and maximum grades?

Asphalt driveways need a slope of at least 1:100 to drain. The maximum grade is not limited so much by asphalt, but by the local council guidelines, which can be as low as 1:6 or 1:4. Check with the local council what the maximum grade permitted in your area is. If it’s less that the slope from your garage to the road, you will need to consult an engineer. 

How is it installed? 

Asphalt is generally not a DIY material; fortunately there are plenty of installers available throughout Australia. 

The installation process generally runs thus: 

  • Excavate 200-300mm
  • Create a base with hardcore of at least 150mm
  • Cover with fine gravel and level it off
  • Ensure good compaction with a vibrating plate or roller
  • Cover with at least 50mm of a 20mm graded aggregate 
  • Cover with 20mm of 10mm graded aggregate

What will an asphalt driveway cost? 

Factors affecting the cost of an asphalt driveway are:

  • Size – length x width
  • Grade – the slope of the driveway
  • Ease of access to the site
  • What edging will be used
  • Preparation costs, such as the need to remove plants or trees and to dig the excavation. 

By having all of these factors at hand, you can ensure you receive an accurate quote.

  • Economical
  • Easy to lay
  • Long lasting (12-35 years depending on climate, use and installation)
  • Can be considered unattractive
  • Limited to one colour
  • Needs resealing every couple of years