Sustainable Solutions to Meet Net Zero Carbon Targets

With the UK government setting a target of net zero carbon emissions by 2050, procuring sustainable building materials has become more important than ever before.

Mastic asphalt is well known for being tough, durable and long-lasting, but what is perhaps less well known is that it is one of the most sustainable and greenest building materials currently available. More and more specifiers, facilities managers and building owners are choosing mastic asphalt for a wide range of green roof applications - from schools to hospitals, office buildings to apartment blocks. Whether intensive or extensive, biodiverse or brown, it is critical that green roofs are built on a solid waterproofing foundation.

Recognised for its environmental performance and aesthetic properties, a green roof system laid with a mastic asphalt waterproofing system enhances the environment, controls storm water run-off and reduces noise and heat transmissions by upgrading the acoustic and thermal performance of a roof. When contractors use mastic asphalt for a green roof system, it eliminates the need for root barriers, which may well have been necessary had a substitute material been used.

Mastic asphalt has one further advantage over other types of waterproof membraneit is carbon neutral - a massive bonus for any building owner anxious to show their green credentials and, when it has reached the end of its useful life, it can be recycled or used as roof screed, minimising the impact on the environment.

The Building Research Establishment (BRE) has officially stated that mastic asphalt is capable of lasting 50-60 years, but MAC has many examples well in excess of this.

For instance, mastic asphalt was first laid at London’s St Paul’s Cathedral in 1906 and it provided well over 100 years’ of effective waterproofing before it needed replacement.

MAC manufacturer member IKO has been involved in many CarbonZero projects across the UK, where the net carbon footprint of projects is entirely offset using internationally approved carbon credits, which means for every tonne of mastic asphalt made, IKO is helping to fund environmental and humanitarian causes.

One example is Westminster Cathedral, the seat of the Cardinal Archbishop of Westminster and the Mother Church for Roman Catholics in England and Wales. In 2015 the existing mastic asphalt was renewed on the roof of the cathedral and during the works some 35 tonnes of mastic asphalt was installed, equating to 5.5 tonnes of CO2 offset.

IKO’s CarbonZero mastic asphalt solution has also been used to renovate Tower Bridge, one of London’s most iconic landmarks which is

Net Zero Carbon

used by thousands of people every day. MAC contractor member Infallible Systems installed over 400 tonnes of mastic asphalt, equating to 50.11 tonnes of CO2 offset.

A major project has also been completed at Four Squares Estate in Southwark, whereby IKO was asked by Keepmoat and Southwark Council to investigate issues relating to the existing access walkways. It was agreed that mastic asphalt would be used for the refurbishment, along with screed repairs and new expansion joints. During the works some 1,400 tonnes of mastic asphalt was applied and in terms of impact, this is the equivalent of 218.4 tonnes of CO2 offset

Back in 2008, the Mastic Asphalt Council made history as the first industry in the world to achieve the CarbonZero standard. Since then mastic asphalt has offset thousands of tonnes of carbon dioxide - underlining its status as a green waterproofing material. Mastic asphalt can help specifiers to achieve the highest BREEAM rating possible as mastic asphalt can be integral in any building design where an A+ rating is required.