For many years mastic asphalt has been the system of choice for waterproofing roofs, flooring and tanking. Now, with a new generation of mastic asphalts offering  greater flexibility, durability and a wide range of colours – this traditional waterproofing material is enjoying a renaissance in the highly competitive car park sector.

Car parks are inherently complex to waterproof as they comprise an array of elements from exposed top levels to heavily trafficked access ramps. Since the rise of multi-storey parking facilities in the 1960s, the application of an all-encompassing waterproof coating has become a critical element in car park design.

As the top deck will be subjected to all forms of weather, which is then transferred to internal levels by cars and pedestrians, the waterproofing specification throughout the car park must be of the highest standard. The traditional approach was to overlay the porous cement screeds and concrete decks with a voidless and totally waterproof layer of mastic asphalt.

Mastic asphalt was always a popular specification on car park projects in the past. More recently, mastic asphalt manufacturers have developed a new generation of mastic asphalts to meet the changing needs of architects, contractors and clients.

A key factor in the material’s resurgence is that the new products contain polymer formulations – giving it more flexibility, durability and consistent quality in application. Also, they can now be coated with an array of attractive colours for car park operators to clearly mark out individual parking spaces, disabled and family bays, and pedestrian walkways.

These modern mastic asphalts are produced in factory controlled conditions and then delivered to site ready for application. This process helps to maintain the quality of the material, whilst also enabling the manufacturer to produce a material bespoke to the project. For example, mastic asphalt can now be formulated to take into account the local climate or specific traffic conditions.

Three factors the contractor must consider when selecting the mastic asphalt to use are; design, budget and timescale. By taking into account the type of traffic (for example cars of HGVs), the available budget and the durability performance required of the material – architects and contractors can specify a mastic asphalt waterproofing and decking system that fits the bill both now and long into the future.