Integrated drainage – clearing water from asphalt surfaces

A key component that can lead to paved surfaces cracking is water. Water can get into any cracks that may be present, causing them to open further as the water expands and contracts with the weather. While asphalt contractors will design and lay paved surfaces that are waterproof, there are times when drainage needs to be integrated into the surface to remove the surface water.

In order to provide effective drainage to paved surfaces, asphalt companies throughout Sydney will work alongside hydraulic engineers throughout the paving process. A number of factors will determine the type of drainage system integrated into the asphalt:

• Size of the paved area – The physical area of the paved surface will determine how much water will remain on it during rainfall and cleaning.

• Average rainfall – based on historical information from the bureau of meteorology, an estimate can be made on the amount of rain expected to fall at any given time. This figure will determine how much water will fall on the surface, and therefore how much needs to be removed

• Soil conditions – not all soils will drain water in the same way. While sandy sites can drain rainwater quite efficiently, clay sites will hold onto the water which can lead to additional pressure as the soil expands.

• Number of stormwater tanks – with a fair idea on how much water will fall on the site, as well as how quickly it will drain away, a stormwater design will be created. This will identify either how many tanks will be needed for effective drainage, or provide a design for drainage into the council’s system.

With a design engineered, it comes down to the skilled asphalt contractors to create the paved surface with the integrated drainage system. Correct falls need to be achieved to ensure the water flows into the drains, and gaps need to be minimised to maintain a watertight surface to prevent cracks.