Discover roofs that clean the air

Improving air quality in cities is critical to making them more liveable and their citizens healthier. Holcim’s Malarkey Roofing shingles remove smog gasses from the air, turning them into water-soluble ions.

Smog-reducing shingle removes pollutants from air, turning them into water-soluble ions

Technology works endlessly, activated by sunlight

Equivalent to the effect of more than one million trees in the last four years

Smog-reducing shingles


Holcim’s Malarkey Roofing shingles contain granules that remove smog gasses from the air following a photocatalytic process that turns them into water-soluble ions.

In the last four years, this technology has been integrated in close to half a million residential roofs. Because each roof has the smog-fighting capacity of three trees, that’s the equivalent of over one million trees of smog-reducing power in four years.

Malarkey Smog-Reducing Shingles: How They Work


The smog-clearing process works endlessly thanks to technology on a microscopic level not visible to the naked eye. Integrated throughout a shingle’s surface, the roofing granules carry a specialized photocatalytic coating. The coating is activated by the sun’s UV rays, while blending into various shingle color combinations.

When sunlight hits the granules, radicals are generated and transform nitrogen oxide gasses into water-soluble ions, improving air quality. The photocatalyst does not get consumed in the reaction, so the smog-reducing capability is a continuous cycle refreshed with rain or dew.


In just a few years, we have seen how quickly our application of smog-reducing roofing granule technology can scale. The opportunity for roofing to help improve air quality is extraordinary. Coupled with our use of upcycled rubber and plastic polymers in the shingles to promote circular construction, we feel that the future is bright for sustainable shingles that make cities greener.

Dale Rushing| President of Malarkey Roofing Products

Making buildings sustainable in use


At Holcim, we are making building greener and improving living standards for all. That is why we are constantly expanding our solutions and products to make smarter options widely accessible to everyone, such as residential roofs that clean the air..

To make buildings sustainable in use, we’re expanding our solutions, ­from roofing and insulation to advanced mortars. Our technologies make buildings more energy-efficient and longer lasting,­ while enabling cooler and cleaner cities with more nature inside.

Holcim is becoming a global leader in roofing systems with a broad range of solutions from green and cool to solar-enabling roofs. We offer a broad range of solutions to make buildings smarter from rooftop to foundation, at every stage of their life, from design and building to repair and recycling.


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