Cool Building Designs Can Be Utilized For Reroofs
by Richard K. Olson, president & technical director, Tile Roofing Industry Alliance
(Editor’s Note: Richard K. Olson is president and technical director for the Tile Roofing Industry Alliance. The association represents industry professionals involved in the manufacturing and installation of concrete and clay tile roofs in the United States and Canada, and works with national, state, and local building officials to develop installation techniques, codes, and standards for better roofing systems. Olson can be reached at firstname.lastname@example.org.)
With the greater awareness for energy efficiencies in building construction, the ability to help move design options for reroof applications are increasing in popularity. While integrated into the new construction markets, design professionals can help educate the reroof market on ways to add efficiencies into projects. In states like California, there are new and evolving code minimums on the energy requirements for the roofing envelope.
When reroof projects allow design assistance, there are a few items to consider. As with new construction, there are several compliance options that can achieve goals and design professionals can provide a full analysis of the energy-efficiency impact of various options.
When reroof opportunities allow discussions, it is a great time to work with the building owner to review the current attic insulation values. The cost to increase the insulative properties can often provide lower cost upgrades to meet higher energy-efficient requirements for the overall roofing envelope. Often, the upgrades of insulation can be performed by the building owner. As an option, there can be the installation of additional insulation above or below the roof sheathing. This provides an added level of heat reduction in the attic areas. In regions such as California, where attics are used for cooling ducts, it will improve energy performance.
Many older buildings have minimum attic ventilation for the overall roofing system. When reroofing, this is a great time to integrate additional ventilation via soffit, gable, and upslope roof vent systems. Increased airflow can reduce attic temperatures in the areas above conditioned living areas. The use of ventilation can significantly increase the level of energy performance.
This form of energy reduction incorporates the installation of a thin layer of code-recognized radiant barrier materials that are generally attached to the attic side of the roof sheathing. There are numerous code-approved products that can be integrated into your roofing designs.
The roof cladding materials can incorporate a number of energy-efficient properties. For some roof systems there is a natural airflow created as an above sheathing ventilation that provides a low-cost barrier. Heavier products with greater density can provide a thermal mass barrier that will reduce the overall heat transfer resulting in lower attic temperatures.
Cladding colors can provide additional energy benefits. The lighter colors provide greater ability to reflect energy back to the sky. Organizations such as the Cool Roof Rating Council® provide formal ratings for reflective properties known as Solar Reflectivity (SR) or Solar Reflective Index (SRI). In California, there are requirements for the various 16 climate zones for minimum SR or SRI for roof claddings and there are aged values that will show the three-year actual aged ratings.
The ability to help create a more energy-efficient roof system will come from the understanding and cost analysis of all the above options. Each of these options can help provide affordable options for even reroof projects. As the demand for greater energy efficiencies increases, there will be new markets for the services of the design professionals that are willing to enter the extensive reroof markets.
Energy efficiencies and compliance options will be a key focus in the upcoming code cycles. In response, the market will see new and innovating products coming out to provide new compliance alternatives. Design professionals need to be in step with the changing market and position themselves to be a stakeholder in the process.