Enabling circular and sustainable re-roofing with Duro-Last®

Roofing systems are a key lever to make buildings more sustainable. With 80% of existing buildings expected to still be in use by 2050, re-roofing represents a tremendous opportunity to decarbonize buildings.

When the Crothersville Junior/Senior High School in Indiana, USA needed a new roof to improve energy efficiency, waterproofing and enable renewable energy, school officials turned to industry leader Duro-Last®, part of the Holcim Group, for a sustainable and circular solution.

The challenge 


The roof at the Crothersville school was 20 years old and in need of replacement. “We want to make sure we don’t have leaks when it rains,” said Dr. Chrystal Street, Crothersville Community School Corporation superintendent. “We want to make sure that no water is coming in. Safety is of the utmost importance, and our roof is part of a strong foundation for us.”

The school also contacted a local energy consultancy to find ways to make the building more energy efficient. The consultancy recommended adding solar panels could reduce the district’s $104,000 annual electric bill by as much as 85%.

The solution


Seeing an opportunity to improve energy efficiency and waterproofing, Crothersville contracted Royalty Roofing to install a sustainable and circular roofing system from Duro-Last. For Royalty Roofing President Andy Royalty and Vice President Darrell Couch, it was a homecoming of sorts – it’s where the two graduated high school.

Royalty removed the old roofing layers down to the existing poly iso board and the material was sent to Duro-Last for recycling. ‘Recycle Your Roof’ is a program where Duro-Last takes back mechanically-attached PVC roofs at the end of their useful life and reprocesses the material into a variety of new, complementary roofing accessories, and commercial and industrial flooring materials.

The new solar-enabling roofing system includes Duro-Last Membrane and Duro-Guard®, Duro-Last’s comprehensive and best-selling range of thermal roofing insulation systems to improve energy and heat loss. The old roof had areas of ponding water, so more drains were added to get water off the roof and away from the solar panels.

The result


Duro-Last’s roofing system both improved the school’s energy efficiency and also enabled a more efficient installation.

The solar panels were installed over the summer of 2022, and by the time school resumed in the fall, they were already converting the sun’s energy into power.

We completed this project in 28 working days. Using Duro-Last custom-fabricated sheets made the process of installing this roof very, very easy. It allowed our guys to move a lot faster than if they were installing any other product.
Jacob Newkirk| Royalty Roofing national sales manager

We’re finding in very competitive situations over the last two years, that Duro-Last stands head and shoulders above the other manufacturers — in manufacturing and delivery — of a complete system for jobs needed in a timely manner.

Dale Sventeck| Royalty Roofing vice president of corporate sales

Holcim's world-leading roofing business

Holcim is a global leader in advanced roofing systems, with leading operations and technologies in the fast-growing USD 40 billion North American market. Today we are #2 in flat commercial roofing and #5 in residential roofing, offering the full range of systems across North America from cool, green and solar-enabled flat roofs to sustainable shingles.

With excellent market positions in North America, Holcim operates 30 production facilities across the US with the most modern and automated operations in the industry. Delivering superior value, Holcim offers the widest range of advanced roofing solutions, from EPDM, TPO and PVC technologies, all the way to sustainable shingles. Our growth is driven by 80% systems selling and 70% re-roofing while supporting our customers in achieving the most sustainable building certifications, from LEED to BREEAM.

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