Driveways are paved from the ground up, so a properly designed driveway 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 smooth 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.
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.
This involves applying a primer to a prepared pavement as a preliminary treatment before the application of a sealant or an asphalt surface. According to Charlie from www.topdrivewaysMelbourne.com.au 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
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.