What is Mastic Asphalt?

Mastic asphalt is a type of asphalt that has a higher asphalt/bitumen (binder) content, usually around 7–10%. Mastic asphalt is heated to a temperature of 210 °C (410 °F) and is spread in layers to form an impervious barrier, usually laid from 18mm – 50 mm thick.

Mastic asphalt has been successfully used to provide unbeatable protection from water penetration for centuries. In recent years the material has been reformulated to include advanced polymers for increased durability, combining its traditional strengths with modern technology. Not simply a roofing material, it is used in various applications, including walkways, floors and roads.

It is highly resistant to all types of weather situation and attacks from thermal shock (rapid temperature changes), which are a frequent source of break down in many other types of membrane.

Fire performance

The high mineral content of mastic asphalt renders it virtually incombustible. Mastic asphalt fulfils all the external fire resistance required for a roof covering and achieves the highest rating (p60) – now (aa) – when tested in accordance with BS.1476 part 3:1975. It has also been tested in accordance with draft European standards prEN1187-1 and prEN1187-2. No significant spread of flame was observed and no flame penetration occurred. Mastic asphalt systems also have LPCP accreditation for fire safety.

Flexibility to allow creativity!

Designing with Colour

To the architect or project manager, mastic asphalt offers limitless scope for design opportunities. It can be specified in almost any colour, texture and design and is an ideal choice where general aesthetics have to be combined with long-lasting waterproofing or paving.

Shell Mexphalte C, with just small amounts of pigment added, puts a huge array of colours and shades at your fingertips, to match your most creative ideas.

With all the established benefits of conventional asphalt, Shell Mexphalte C offers limitless design freedom to architects, landscape designers, civil engineers and town planners.

With coloured mastic you can:

  • Highlight areas with bold colours
  • Blend them harmoniously into any environment
  • Mark out footpaths and bicycle lanes
  • Brighten parks, squares, play areas and sports grounds
  • Highlight roundabouts and bus-stops
  • Enhance entrances to “historic and heritage sites”

Coloured mastic asphalt promotes new standards of safety around critical places like schools and pedestrian areas.

Why Use Mastic Asphalt?

The benefits of using mastic asphalt include:


Mastic asphalt is the premier bituminous waterproofing and surface product available, that has the ability to last up to 60 years unlike a traditional tar macadam surface. The polymers used in mastic asphalt improve elasticity in both hot and cold weather conditions, which help to maintain its structural integrity and durability.

Durability & Cost Effective

Mastic asphalt is 100% waterproof and a seamless material that is second to none. It outlasts all other bituminous materials and can withstand heavy industrial use. It is weed and dust resistant.

Health & Safety

Unlike brick and block paving, mastic asphalt paving is laid in a continuous film without the need for joints, this means that accidents such as slips, trips and falls are reduced. Mastic asphalt provides a safe anti-slip surface for pedestrians and an anti-skid carriageway for vehicles.

Maintains its Appearance

Mastic asphalt can also be made fuel and acid resistant and can be cleaned with pressure water jets without effecting the surface.

Environmentally Friendly

Mastic asphalt is a non-toxic product and is fully recyclable. It is also a carbon zero product and a 100% CO2 neutral solution.


Because of its molten state it can be moulded to any irregular shape and be laid around any obstruction, whether it is inside or outside.

Speed of Project Completion

Mastic asphalt can be laid quickly over almost any large area. It does not require the use of heavy equipment, it is flame free and within a few hours the surface is ready to use.

Domestic and Commercial Flooring

As well as a proven damp-proof membrane mastic asphalt when applied to domestic floors, provides an ideal base for carpet, vinyl and other types of smooth flooring. Its speed of application and fast cooling properties allow carpets and furnishings to be replaced within hours.

There are no moisture considerations, curing or drying out times with mastic asphalt floors.