As a Certified Master Commercial Roofing Contractor with GAF, they are our preferred vendor for TPO roofing. We are able to offer building owners anywhere from 10, 20 and 30 year No Dollar Limit Warranties to provide piece of mind that the roof has been inspected by the manufacturer who will pay for labor and materials if there is ever a problem down the road with the install or the material. Duro-Last is similar to TPO, but all materials come from the same manufacturer, along with a great warranty as well.