A Bitumen Spray-Seal is a combination of sprayed bitumen that waterproofs the road – driveway or car park followed by a wear coat of aggregate. Different aggregate sizes are selected depending on the intended use of the surface Each of the 2 coats of bitumen and 2 coats of aggregate are laid at different rates specified by the contractor or engineer to meet the correct requirements. There are many different ways to carry out a bitumen seal with a multitude of bitumen types, spray rates, aggregate sizes and so on. A seal must be designed for your specific site considering the type of base, traffic volumes, life expectancy just to name a few key points. A bitumen spray seal can be done as either single coat seal or a Two coat seal.