Flat & Low Slope Roofs

Why Choose a Duro-Last® Flat Roof

Duro-Last has been the industry leader in manufacturing and marketing custom-prefabricated single-ply membrane roofing systems for flat or low slope roofs since 1978.


Durability = True Performance

The unique formulation of Duro-Last Roofing Systems delivers long-term value and peace of mind. Two differentiators Duro-Last offers are a high-quality reinforcement scrim and thickness above scrim.

  • Roof membrane is manufactured with 28 mil of thickness on the top performance layer, far exceeding industry standards as well as competitor systems with equal and even greater mil values
  • Only product in the marketplace to offer prefabrication of the entire roofing system
  • Offers a complete line of Duro-Last custom prefabricated accessories
  • Single ply membrane has a weft-insertion anti-wicking scrim with a density of 18 by 14 threads per inch — among the highest in the industry
  • Unique in the industry, Duro-Last offers a 15-year warranty with consequential damage coverage for Duro-Last prefabricated roofing systems with no additional charge

Our Approach

We will assist you through every phase of your flat roofing project, from the planning phase through the installation and well beyond. Nasi Roofing takes a holistic approach to roofing, providing complete roofing services.

  • Detailed descriptions of existing roof conditions with professional recommendations
  • Plans, detailed drawings, and specifications
  • 15-30 year materials and labor warranty options
  • Insured, licensed, and bonded
  • Long term planning, inspections, and budgets

We have the flexibility to meet aggressive schedules without interruptions during installation and provide the highest level of quality so your roof will remain leak proof for years to come. Over the years, we have seen just about every type of roof problem on every type of building. Size doesn't matter. From the 1,000 square foot downtown store to the 100,000 square foot industrial complex — we're your Wisconsin flat roofing experts!

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Available Roofing Colors

Duro-Last Roofing Colors

Make the Right Choice

Choose our Wisconsin roofing company and the Duro-Last roofing system for the following reasons:

  • Our ability to address and solve all of your specific roof problems
  • 15-30 year materials and labor warranty options
  • 12 million dollar consequential damage liability insurance policy
  • Minimal disruption to your business
  • Can meet your schedule
  • Our record of satisfied customers

To ensure expert installation, every job our Wisconsin roofing company completes is inspected by a Duro-Last Quality Assurance Technical Representative.

Duro-Last Roofing Awards

Proven Protection

The durability of the membrane and backing by the industry's best warranties are only a couple of the reasons the Duro-Last roofing system is the only roofing system Nasi Roofing will install.


The Midwest has many different types of weather conditions, and you need a roof that can withstand it all! Duro-Last offers over three decades of proven PVC roof system performance with billions of square feet of membrane installed across North America.

Nasi Roofing has been an authorized Duro-Last contractor, installing throughout Wisconsin and Michigan since 1983. We have installed and warrantied over 2,000 roofs totaling over 10 million square feet of membrane. Our Wisconsin flat roofing company is consistently listed among the top Duro-Last contractors in the nation.

World's Best Roof

Prefabrication = Fewer Leaks + Better Installation

Up to 85% of the seams are completed in a factory-controlled environment which dramatically reduces the potential for leaks — and adds the advantages of a faster, quieter, and easier installation, with less maintenance and reliable roof performance for years to come.

UL Platinum Certified

Certified Energy Efficient, Durable, and Sustainable

By reflecting up to 88% of the sun’s energy, the reflective white Duro-Last Roofing System can greatly reduce energy costs. Duro-Last leads the flat roofing industry in certifications under the NSF American National Standard for Sustainable Roofing Membranes – NSF/ANSI 347.

Exceptional 20 Year Roofing Warranty

Backed by the best warranty in the roofing industry

Duro-Last's 15, 20, 25, and 30 year commercial roof warranties provide you with maximum protection. While other flat roofing manufacturers offer limited warranty coverage, Duro-Last provides the world's best material and labor warranties. No small print and no additional cost to you.