Bitumen is the black sticky product derived from crude oil; Bitumen is the binding agent that waterproofs the road surface. While asphalt includes between 4 to 8 percent of bitumen the asphalt mixes are similar to a cake mixture including bitumen, sand, metal dust, lime.

With professional installation and regular care, quality asphalt typically lasts 20 to 30+ years. In contrast, a standard bitumen spray seal usually has a lifespan of about 10 to 15 years.

Bitumen surfaces are placed between 120 degrees Celsius and 220 degrees Celsius. 

• In spray seal applications the bitumen is heated to (between 150 to 200 Degrees) allow it to flow, once the bitumen flows we can spray the product from a speciality sprayer to apply specified designed layers to the gravel pavement surface.
• Asphalt raw materials (sand, aggregate, metal dust, lime) are heated in an asphalt mixing plant to expel all of the moisture out of the stone, this leaves micro air pockets in the surface of the stone, then when hot (150 to 180 degree) bitumen is sprayed onto the heated blend the bitumen actually absorbs into the air pockets of the stone locking all the material together like a cake mixer.

The requirement for millimetre (mm) accuracy in asphalt placement is not just about a smooth finish; it is a critical engineering standard that directly impacts the longevity, safety, and cost-efficiency of a road.

Why Millimetre Accuracy Matters

• Optimal Material Usage: Millimetre precision ensures the exact amount of asphalt is laid. Even a small over-application across a large project can waste tonnes of expensive material, while under-application leads to weak spots.
• Structural Lifespan: Asphalt thickness directly relates to its load-bearing capacity. Insufficient thickness (even by 5-10mm) can lead to premature fatigue cracking, rutting, and base layer exposure, significantly shortening the road's life.
• Water Drainage & Safety: Roads must have a precise "fall" to direct water away. Millimetre accuracy prevents water pooling, which is a major cause of potholes and dangerous aquaplaning (hydroplaning) for drivers.
• Ride Quality (IRI): High-speed roads are measured by the International Roughness Index (IRI). Precision placement eliminates localized "bumps" that cause vehicle wear and driver discomfort.