IKO’s Mastic Asphalt roofing solution utilised to renew Westminster Cathedral

In 2014, IKO were approached by Westminster Cathedral’s architect to discuss renewing its Mastic Asphalt roof coverings with our IKO Permaphalt Polymer Modified Mastic Asphalt System.

We assigned the job to Knight Asphalt – one of our approved contractors – who installed around 35 tonnes of IKO Permaphalt throughout the project.

Westminster Cathedral is a stunning church in the heart of London and, from its 64-metre-high viewing gallery, boasts spectacular views over the streets of the city.

IKO’s range of specially formulated Mastic Asphalt roofing solutions, use advanced polymer technology giving the ideal combination of long-term durability, increased fatigue resistance, improved temperature stability and ease of installation.

For this particular project IKO Permaphalt system was utilised due to its range of market leading benefits including; a completely seamless waterproofing finish, high temperature stability, enhanced fire performance ratings due to IKO Permaphalt being virtually incombustible, excellent acoustic performance, being suitable for roofs exposed to foot traffic, environmentally friendly – part of our Carbon Zero initiative – and being covered by a comprehensive range of long term guarantees.

Mastic Asphalt providing an environmentally friendly project from start to finish

Here at IKO, we and our contractors are always thinking about the impact of our work, and, thanks to our commitment to supplying Carbon Neutral Mastic Asphalt, we were able to calculate the impact Westminster Cathedral’s work had on the population.

For every single tonne of Mastic Asphalt we make we contribute to environmental and humanitarian causes, and, for this project alone, the result was 5.5 tonnes of CO2 offset.

The net carbon footprint of this project is entirely offset using internationally approved carbon credits, which means for every tonne of Mastic Asphalt made, we are helping to fund environmental and humanitarian causes.

Here’s a breakdown of our impact by sector for the Westminster Cathedral project.

Impact sector, impact, and quantitative data


  • Wood saved – 3 tonnes.
  • Area protected – 0.01 hectares.


  • Number of stoves – 1.
  • Time saved – 67 hours.
  • Children impacted – 3.
  • Elderly people impacted – 1.
  • Total people impacted – 5.


  • Working time saved – 67 hours.
  • Working days equivalent – 8 days.

Health – likely reduced cases from project support:

  • Respiratory illnesses (lower chest/lung) – 1.
  • Asthma – 1.
  • Ear, nose, and throat irritation – 0.
  • Total reduced instances of series illness attributed to indoor smoke – 2.

The history of Westminster Cathedral

Westminster Cathedral is the largest Catholic church in England and Wales and the ground it sits on was purchased by the Archdiocese of Westminster back in 1885.

It took until the late 19th century for the Catholic Church’s hierarchy to be restored in England and Wales, and the first large sum of money for the now Westminster Cathedral was raised in memory of a man called Cardinal Wiseman – who was the first Archbishop of Westminster and passed away in 1865.

After Wiseman passed the land was occupied by the second Tothill Fields Bridewell prison for some time until his successor, Cardinal Manning, acquired it in 1884.

Construction works eventually began in 1895 after two false starts; one in 1867 under an architect called Henry Clutton and another in 1892 under Baron von Herstel.

It was Manning’s successor, Cardinal Vaughan (the third archbishop), who finally built the cathedral with an architect called John Francis Bentley, who incorporated a lot of Byzantine architecture into his designs.

Unfortunately, Bentley passed away a year before the cathedral opened its doors in 1903 and, although Vaughan was around for the grand opening, he died soon after on 19 June 1903.

IKO produce an incredible array of Mastic Asphalt solutions perfect for an array of applications from car park deck and highways resurfacing to roofing.

If you have any queries or questions regarding this project or need to discuss your next project in detail utilising our Mastic Asphalt solutions don’t hesitate to contact us today.

Latest news