Cool Roofing System

Cool roofing and reflectivity has been an increasingly important factor in commercial roofing, and the Duro-Last® Cool Zone® roofing system has set the standard for single-ply roof reflectivity and the resulting savings in energy usage. Duro-Last commercial roofing installed by Alternative Roofing Systems is setting the bar for terms like sustainability, cool roofs and cool roofing.

But what do terms like sustainability and cool roofing really mean to building owners, facility managers, contractors, architects, and others? It means that the design, construction, maintenance, life-cycle impact, adaptive re-use, destruction, and recycling of roofing components must help to meet the short and long-term environmental standards in high demand by today’s high-performance buildings.

To be considered “sustainable,” a roofing system needs to meet the Five E’s of high-performance roofing: Energy, Environment, Endurance, Economics, and Engineering. In each of these important areas, the Duro-Last Cool Zone roofing system leads the commercial roofing industry. We invite you to learn more about the Five E’s and how the Duro-Last Cool Zone roofing system delivers on the multiple demands of high-performance roofing.

Learn more about the Five E’s:

Reflective Roofing Systems

Save energy with Duro-Last Cool Zone RoofingA high-performance roof can be a powerful factor in reducing energy consumption by becoming an energy efficient roof – henceforth a Cool Roof. When used with appropriate insulation on low-sloped or flat roofs, a high-emissivity Duro-Last Cool Zone reflective roofing system can:

  • Reduce a building’s energy consumption by up to 40 percent
  • Improve insulation performance and reduce winter heat loss and summer heat gain
  • Preserve the efficiency of rooftop air conditioning
  • Potentially reduce HVAC capacity requirements
  • Decrease the effects of Urban Heat Islands and related urban air pollution

The Duro-Last Cool Zone reflective roofing system exceeds “cool roof” standards set forth established by these organizations:

  • The EPA’s ENERGY STAR® Roof Products Program has established a minimum standard that requires low-slope reflective roof products to have an initial reflectance of at least 65 percent, and a reflectance of at least 50 percent after three years of weathering. If there is any doubt about whether a roofing system is “cool roof” or energy efficient roof, check to see if it is listed in the ENERGY STAR Roof Products listings at Use their online calculator to determine potential energy savings for your building.
  • The Cool Roof Rating Council (CRRC) is a non-profit association that implements and promotes fair, accurate performance ratings for solar reflectance and emittance from roof surfaces. All tests for measuring relective roofing properties are performed by accredited, independent laboratories following established ASTM International protocols. Performance data for products from numerous manufacturers can be found on the CRRC’s web site at
  • Title 24 of California’s Energy Efficiency Standards for Residential and Nonresidential Buildings is a wide-ranging “green” construction bill that became effective in October, 2005. Title 24 specifies that new and replacement commercial roofs – virtually any low-slope roofing project that requires a construction permit – must have a minimum initial thermal emittance of 75 percent, and a minimum initial solar reflectance of 70 percent, as rated by the Cool Roof Rating Council.

Other Important Energy Considerations:

  • The American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) established Standard 90.1 as a minimum requirement for energy-efficient building design. President Bush signed legislation offering tax deductions to buildings that exceeds the 90.1 Standard.
  • Lawrence Berkeley National Laboratory recently determined that increasing the R-value of a roofing system in Los Angeles from R-9 to R-15 would reduce annual energy costs by $2,500 and lower carbon dioxide emissions by thousands of pounds.
  • Executive Order 13123, now known as Federal Acquisition Regulation Case 1999-011, mandates that federal office buildings must reduce energy usage 30% by 2005, and 35% by 2010. It also mandates that federal industrial buildings and laboratories must reduce energy consumption 20% by 2005, and 25% by 2010. Federal agencies also must use ENERGY STAR products when available, and decisions must be based on energy and life-cycle cost analyses.
  • In cooperation with state and local governments, many utility companies offer rebates for using reflective roofing systems. These rebate programs are offered nationwide, not just in southern climates. For instance, Excel Power, the fourth largest utility company in the United States, has awarded rebates as far north as Minnesota.
  • Energy efficiency also reduces pollution by mitigating the urban heat island effect (see

Better for the Environment: Inside and Out

Save the environment with Duro-Last Cool Zone RoofingA popular definition for sustainable roofing was developed during a workshop held at the Oak Ridge National Laboratory (ORNL) in 1996: A roof system that is designed, constructed, maintained, rehabilitated and demolished with an emphasis throughout its life cycle on using natural resources efficiently and preserving the global environment.

The Duro-Last Cool Zone roofing system can minimize environmental impact in several ways:

  • Duro-Last is a member of the U.S. Green Building Council ( The USGBC’s Leadership in Energy and Environmental Design (LEED) voluntary rating system is an increasingly popular means for helping building owners determine environmental performance of building components. The Cool Zone system can help in obtaining credits toward LEED and LEED-EB certification.
  • Our closed-loop manufacturing process recycles production scrap, benefiting waste reduction
  • Because the roofing system is lightweight, less fuel is needed to transport it to the job site than other systems
  • The Duro-Last Cool Zone system can often be installed over an existing roof, reducing waste, landfill space and disposal costs. Oak Ridge National Laboratories (ORNL – recently estimated that 9-10 million tons of non-recyclable roofing waste is sent to U.S. landfills every year
  • Duro-Last offers a “Recycle Your Roof” program, which can reduce disposal costs of existing PVC roof membrane tear-offs when a tear-off is required.
  • At the end of its life as a roof, the Duro-Last Cool Zone roofing system can be recycled into other useful products such as specialty flooring (as demonstrated by Oscoda Plastics Inc., Duro-Last’s sister company) and other products.

Endurance  Passing the Test of Time

The Duro-Last Cool Zone roofing system boasts high enduranceIn terms of High-Performance Roofing, endurance is the ultimate reflection of the performance of every roofing component in terms of reliability, water absorption, wind and fire resistance, maintenance, and repair. No matter how “cool” or “green” a roof is, it still has to protect the building – for years – in all types of weather – a reality that is sometimes neglected in sustainability discussions.

If you’re looking for a roof that will last, consider our track record. More than one billion square feet of Duro-Last membrane have been installed throughout the U.S. since the late 1970s – and many of these roofs are still in service. What makes a Duro-Last Cool Zone roofing system so durable? Each roof we make is:

  • Resistant to water, fire, chemicals, grease, and punctures
  • Able to stand up to all types of weather – including high winds and extremes of hot and cold
  • Virtually maintenance free, unlike other roof materials that may require regular patching and repairs
  • Reinforced with a high-density weft-insertion scrim for exceptional strength and durability
  • Confidently backed by the industry’s best warranties. Duro-Last protects commercial and industrial building owners with either a 15-year full warranty or a 20-year prorated warranty. Both are transferable, and both provide maximum protection. Our standard warranty includes coverage for consequential damages that result from defects in the Duro-Last material and/or installation.

Not only does a Duro-Last Cool Zone roof perform well over the years, it can actually help extend the useful life of other building components. By keeping moisture out while reflecting ultraviolet (UV) and infrared (IR) radiation, it can help to protect underlying insulation and the roofing substrate from deterioration.

To help promote Endurance for the long-term, building owners should ensure that a new roof:

  • Is properly designed for the location, climate, roof deck and type of building
  • Is installed professionally. Defective workmanship accounts for roughly 30 percent of roofing failures
  • Has physical properties that will stand the test of time: solar reflectance and emittance, tensile strength, water absorption, fire resistance, wind uplift, elongation and thermal expansion, dynamic puncture resistance and resistance to rooftop contaminants such as acid rain and air pollution
  • Is inspected and maintained regularly. This includes limiting the access and traffic on the roof

Better Economics Over the Long Term

The Duro-Last Cool Zone Roofing System will save you money.While some types of roofing may have lower initial costs, the true costs of a roofing system are measured over its total life cycle. These include maintenance and repair costs, energy savings, and tear-off and disposal costs. Clearly, economics is a very important criterion for building owners, and High-Performance Roofing systems must be economical if they are to become viable, real-world options.

A Duro-Last Cool Zone roofing system delivers excellent life-cycle economics. Key benefits include:

  • Reduced installation costs through custom factory prefabrication
  • Low maintenance and repair costs
  • Protection from interior damage costs through leak-proof performance
  • Elimination of extended warranty costs
  • Savings incurred through reduced energy consumption, and related rebates or incentives

In 2004 – before the most recent energy price increases – a 20-year comparison was prepared with the help of independent Midwest roofing contractors. The objective was to compare the life-cycle costs of a High-Performance Roofing system – in this case, a prefabricated white PVC single-ply – with popular black EPDM and BUR systems for a fully-warranted, 50,000 square-foot re-roof in the Midwest. This hypothetical comparison clearly demonstrates the impact that an energy-efficient, High-Performance Roof can have over time.

View the comparison chart

Expert Engineering Enables Long-Lasting, Money-Saving Performance

Duro-Last Cool Zone Roofing System saves you money with highly efficient engineering.Smart, coordinated engineering and design is not only the essential enabler for the other “E’s” of High-Performance Roofing, it is the key to what the Department of Energy calls “whole-building design”, which integrates all the subsystems and parts of the building to work more effectively together from “cradle to cradle”.

Stringent measures help ensure that the highest level of quality control is implemented throughout the manufacturing process. From raw material selection to job site delivery, at least 14 different Duro-Last personnel inspect, evaluate, and qualify the materials and processes that are used to produce the Cool Zone roofing system.

Every Cool Zone roof is engineered as a completely integrated system, prefabricated to the exact measurements of each building. Not only is up to 85 percent of membrane seaming completed in a factory-controlled environment, roof stacks, flashings, and edge details are also completed at the factory and shipped to the building site as part of the complete roofing system. The few remaining seams are then hot-air welded on-site by an approved contractor and inspected by a Duro-Last technical representative before a warranty is issued.

Thanks to the precision fabrication of the Cool Zone roofing system, installation is much faster and less disruptive than for a typical “roll-goods” roof. The installation process is quiet, with no noxious fumes or flames, so building occupants can continue with their regular routines.

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Looking for help with a commercial roofing project? As a leading certified Duro-Last roof installer in the Seattle area, we are qualified to meet your commercial, flat, and low slope roofing needs. Contact us today!