Polymer Modified Asphalt

Service Details

Mastic asphalt has been used as a waterproofing material in the UK for well over a century. At Capital Roofing, we have a long and successful history with asphalt roofing, including multiple national awards from the IMA (Institute of Mastic Asphalt) and the MAC (Mastic Asphalt Council). Our asphalt teams are among the most decorated in the industry.

Modern polymer modified asphalt builds on the traditional material by incorporating polymer additives that improve flexibility, fatigue resistance, and low-temperature performance. Traditional asphalt can become brittle in cold weather and crack under building movement. Polymer modification addresses both of these issues, resulting in a material that is more forgiving and longer-lasting than its predecessor.

Asphalt roofing is applied hot, in two coats, to build up a solid, seamless waterproofing layer typically 20mm thick. The material is spread by hand using specialist tools and skill developed over years of practice. There are no joints, no seams, and no fixings to fail. When correctly applied to a properly prepared substrate, an asphalt roof will provide 30 to 40 years of watertight service, and many asphalt roofs in London have lasted considerably longer.

The material is particularly well-suited to roofs that need to withstand foot traffic, because it is inherently tough and can be finished with a solar reflective coating or paving slabs for heavy-traffic areas. Rooftop plant rooms, terraces, and access walkways are all common applications. Asphalt is also the traditional material for tanking basements and below-ground structures, where its monolithic, jointless nature makes it the most reliable waterproofing option.

We carry out both new asphalt roofing installations and refurbishment of existing asphalt roofs. Many buildings in London, particularly post-war social housing blocks and commercial buildings from the 1960s and 1970s, have original asphalt roofs that are now reaching the end of their service life. In many cases, a new polymer modified asphalt overlay can be applied over the existing surface, avoiding the cost and disruption of a full strip.

Our asphalt roofing operatives are MAC registered and IMA trained. We hold Competent Roofer certification for asphalt work and can issue Building Regulations compliance certificates for domestic projects. All work is carried out in accordance with BS 8218 and current best practice guidance.

For asphalt roofing surveys and quotations in London and the South East, please contact our Blackheath office.