A well-constructed asphalt driveway adds to the value of any home and will last for decades with little or no maintenance. It is important to understand how a driveway should be laid out and asphalted. This ensures that when it’s time to have your driveway repaved, or when building a new home, the job will get done right.
Driveways are paved from the ground up, so properly designed driveways Melbourne needs a well-planned sub-grade before paving with asphalt. The sub-grade must be smooth and dry and compacted. Clay soil should be removed and replaced with soft sandy soil, often with a layer of aggregate on top several inches thick. The asphalt layer (often it is done in two or more layers) that is paved on top of the aggregate should have a compacted thickness of at least 2 inches. Compacted asphalting is about ¾ as thick as loose hot asphalt mix.
The driveway should slope from its centre down towards the edges of the pavement to allow water to drain away and to avoid ponding on the surface of the asphalting. Ponding degrades the asphalt over longer periods of time. The asphalting should have a slope from its crown to the edge of about ¼ inch per foot. Drainage can also be achieved by paving with porous asphalt, which is a special mixture that allows the water to drain through the porous asphalt into a sub-ground reservoir. If using porous asphalt, ensure that it meets local impermeable surface codes. It is important to note that water should drain away from any buildings and there must not be ponding of water at the edges of the asphalting.
Full-depth asphalting is when the asphalt is laid directly on top of the soil sub-grade. This keeps water out of the pavement as it drains away into the soil. The soil sub-grade should be firmly compacted and a full-depth asphalt pavement should be at least 4 inches thick, although 5 to 6 inches is preferable. If using compacted aggregate as a base then the base should be at least 6 inches thick and the asphalt pavement on top should be 3 inches thick.
This involves applying a primer to a prepared pavement as a preliminary treatment before the application of a sealant or an asphalt surface. When having your driveway sealed or recoated with asphalting, the primer penetrates the prepared surface and creates a bond with the sealant or asphalting that is applied afterwards. It also provides temporary waterproofing of the prepared surface. The choice of primer depends on several factors:
- The pavement material type and surface porosity.
- The weather conditions.
- The timing and the type of the final treatment (sealing or asphalting).
When to Lay Down Asphalting
Most hot asphalt mixes require atmospheric temperatures of at least 20° C to give the work crews enough time to lay and work the asphalting. Rolling and compacting have to start as soon as the asphalting can be compacted without displacement and should continue until the mix is completely compacted and there are no roller marks. If the temperatures are too cold, the mix will cool too quickly before the asphalting can be properly rolled and compacted. Dry weather conditions are also essential to any successful paving job. For this reason, most asphalting gets laid in summer or early fall at best, depending on what part of the country you live in.