FAQ’s & Terminology

Here are some of the frequently asked questions we get from customers. If you have a question that isn’t answered below, contact us and one of our friendly team will get back to you.

frequently Asked Questions

What are the different types of asphalt?

Commonly used asphalts in the UK are asphalt concretes (previously termed ‘bitmacs’ or ‘bituminous macadams’):

  • Hot Rolled Asphalts (HRAs)
  • Stone Mastic Asphalt (SMAs)

Asphalts can further be grouped into road base, binder and surface courses, each providing a different function.

What depth should I lay asphalt?

To ensure a quality finish the depth should be at least 4 times the dimension of the largest nominal size in the mix for the surface course (i.e. 40mm depth for 10mm asphalt concrete).

What is the British & European standard for laying asphalt?

BS EN 13108-1 – Bituminous mixtures, material specifications and asphalt concrete.

BS 594987 – Asphalt for roads and other paved areas, the specification for transport, laying, compaction and type testing protocols.


Asphalt Concrete (AC)

A mineral aggregate bound together with asphalt, laid in layers and compacted, being mainly aggregate based gives the mix its strength.


Also known as asphalt, black sticky substance which is a semi-solid form of petroleum.


Pre-coated chippings are applied to hot-laid material and rolled in to form a skid resistant surface.

Hot Rolled Asphalt (HRA)

A dense mixture of mineral aggregate, sand, filler and bitumen. There is a high proportion of sand in the mix resulting in a low percentage of air voids. The mortar of bitumen, sand and filler gives HRA its strength resulting in a hard wearing long life surface.

Methyl-Methacrylate (MMA)

Line marking using a cols plastic technology that is resistant to the heat and cold. Extremely durable and the best method in places with high volumes of traffic.


Refers to the removal of the top layer of the surface prior to the application of a new surface course.

Stone Mastic Asphalt (SMA)

A dense wearing course material filled with a mastic of aggregate, filler and binder. Ideal for low-speed roads.

Thermoplastic Line Marking

Also called hot melt marking paint, a hot melt kettle is used to heat the paint to 200°C then sprayed to the road surface. This paint provides a thick coating, wear-resisting, bright and reflective result. Mainly composed of synthetic resin, glass beads can be added to the material to help enhance reflectivity.