13 Questions to ask When Specifying High-Performance Roof Systems

August 11, 2010

What's covered under the warranty? What are the annual repair and maintenance costs? Does the manufacturer have a recycling program?

There's a lot to consider when shopping for a roof system, especially if you're looking for a high-performance solution—one that's not only durable and economical, but also energy efficient and environmentally friendly. Saginaw, Mich.-based manufacturer Duro-Last Roofing has formulated the following list to help Building Teams specify high-performance roof systems.

1. Does the roof meet Energy Star criteria? The Energy Star roof products program has established a minimum standard that requires low-slope roof products to have an initial reflectance of at least 65%, and a reflectance of at least 50% after three years of weathering. If there is any doubt about whether a roofing system is “cool” or energy efficient, check to see if it is listed with Energy Star (www.energystar.gov). The Cool Roof Rating Council (www.coolroofs.org) also rates roofing systems for solar reflectance and emittance.

2. Does the roof meet the ASHRAE 90.1 standard, making it eligible for federal tax deductions? The American Society of Heating, Refrigeration, and Air Conditioning Engineers established standard 90.1 to set minimum requirements for energy efficient building design. Adopted by the federal government in 1994, it sets the roof reflectance minimum for government facilities at 70% and the minimum emittance level at 75%.

3. Is a system LCA available? LCA, or life cycle assessment, is a science-based measurement of the environmental impact of a product through its entire life cycle, including material extraction costs, manufacturing waste, embedded energy, and potential for recycling and reuse. (See BD+C's White Paper on LCA at: www.bdcnetwork.com/contents/pdfs/bd&clcawhitepaper.pdf.)

4. Is a roof tear-off required? In re-roof projects, an important environmental consideration is minimizing waste. Certain roofing systems can be installed over existing roofs, thereby speeding construction time, lowering costs, and reducing the number of runs to the local landfill.

5. Does the manufacturer have a recycling program? Some manufacturers have initiated recycling programs to collect materials once their useful life has expired. This waste is being recycled into useful products such as park benches, flooring, and new roofing components.

6. Does the roof system moderate temperatures in summer and winter, even without air conditioning? Cool, green, and solar-integrated roof systems can help moderate indoor air temperatures, even in buildings without air conditioning, such as warehouses and factories. This helps lower energy costs and may even improve worker productivity.

7. Does the system provide one- or two-way ventilation? Vented roofing systems can help reduce moisture and mold while relieving positive air pressure, allowing buildings to “breathe.” While both one- and two-way ventilation are helpful, a study by the Army Corps of Engineers concluded that two-way vents are more effective for moisture evaporation.

8. What is the roofing manufacturer's reputation? This may be the most crucial question of all. Make sure to find out answers to questions like:

  • Does the manufacturer inspect the roof after installation?

  • Does the manufacturer train, monitor, and grade contractors?

  • What is the range of service longevity for this type of roof system with this manufacturer in this area?

  • What have been the primary reasons for system failure with this type of roof? How were they resolved?

  • How much maintenance will be required? How often?

9. How long is the warranty? Make sure to find out the length of the warranty, if it covers the entire roof system, including installation defects, and if there are any exclusions and fees in the warranty for issues such as ponding water and consequential damages.

10. Can the manufacturer provide LCC analysis? Building owners consider life cycle costs one of the most important traits of a roof system. LCC analysis should include installation costs, including tear-off and disposal costs; estimated fees for annual maintenance; repair costs; and potential energy savings over the life of the roof.

11. Can the system be pre-fabricated? Certain roofing technologies can be factory manufactured to precisely fit a building. This approach can potentially reduce waste, speed installation, and reduce the risk for error.

12. Is this the best roofing system for this roof deck?This building type? This climate? Certain systems may not be ideal for certain building types and locations. For example, a “cool” roof may not be beneficial in traditionally cool climates. Make sure to consult with a roofing expert to determine which systems are ideal for your building.

13. What's the proper way to design and engineer the roof system? Roofing authority Carl Cash, PE, has estimated that defective design and engineering accounts for about half of all roofing failures. Key considerations include drainage, wind-related design, insulation, fire resistance, thermal expansion, tensile strength, puncture resistance, and watertight performance.

         
 

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