One of the biggest advantages that the Duro-Last roofing system has to offer is its low maintenance.  According to the National Roofing Contractor's Association. a modified asphalt roof system will require maintenance, leak repair, coatings, re-sealing and up-keep following the sixth to eighth year of use, at $0.15 per square foot-per year until year 15 when the amount doubles.  With the Duro-Last roof system there is virtually no maintenance required for the life of the roof.  Furthermore maintenance contracts and re-sealing's are a thing of the past with the Duro-Last roofing system.  With an asphalt roof system, any roof that is 2,000 square feet will cost you possibly $300 per year through years eight through 15, which is an extra $2,400 you will spend on maintenance and repairs for the life of the roof.  Plus you'll have the extra headaches and risks of having a potentially faulty system.