products and systems aimed at meeting DoD’s energy- and water-conservation goals. ESTCP recognizes the military must find systems and technologies whose per- formance can be demonstrated and then transferred to any building in DoD’s inven- tory. A grant to achieve this with integrated metal roofing technology on Goodfellow Air Force Base, San Angelo, Texas, was awarded in 2011. The new metal-over-metal retrofit roof integrates cool roofing, solar- power generation, solar thermal, rainwater catchment and above-sheathing ventila- tion in one holistic system that is being monitored by Oak Ridge National Labora- tory, Oak Ridge, Tenn.
Metal Roofi ng Benefi ts The word “steel” conjures images of
ONGOING SERIES
This article is the third part in an ongoing series about the integrated metal roof retrofit assembly at Goodfellow Air Force Base, San Angelo, Texas. The first part in the series appeared in retrofit’s September- October 2012 issue, page 30, and was an overview about the demonstra- tion project. The second part was published in the November-December 2012 issue, page 34, and focused on the roof’s integrated solar-power and -thermal system. The fourth install- ment of the series will appear in the March-April issue and will cover the in- sulation technologies used in the retrofit assembly.
strength and durability. Steel is used in highway and bridge construction for its strength. Steel is used in cars for safety. Steel is used in the military for its ability to protect our service men and women. Steel also can be used in residential and commercial roofing in a light flat-rolled configuration. The reasons are the same as for other uses: It is strong; light weight; non-combustible; resistant to hail, wind and weather; and features almost unlim- ited aesthetics and design flexibility. For decades, our nation’s military has used metal roofing for new construction, reroofing and retrofit projects. In fact, DoD’s “Base Structure Report” estimates more than 1.85 million square feet of metal roof retrofits have been installed on military and federal facilities in the U.S. It is further suggested that another 617 million square feet of single-story military buildings will receive metal roof retrofit- ting.
Military buildings with roofs more than
25-years old generally need new roofs and insulation, ventilation and rainwater/ drainage improvements to meet current building standards. New mandates for saving energy, producing energy at lower cost and establishing independence from the grid also must be considered. This is no small task, but integrated systems may be the answer for energy savings and greatest design flexibility.
34 RETROFIT // January-February 2013 PHOTOS: GOODFELLOW AIR FORCE BASE
The nature of a holistic, integrated
metal roof retrofit option led to ESTCP’s selection of a metal-retrofit demonstra- tion project at Goodfellow AFB. The project involves an existing metal roof retrofitted with a new 24-gauge prepainted Galval- ume steel standing-seam roof system. Standing-seam steel roofing is created
with roof panels that are mechanically interlocked together with a mastic in the seam joint to provide a watertight roof sys- tem. The attachment clips are concealed but mechanically attached to the sub- structure of the building framing, meeting all building-code requirements for design loads and resistance to wind uplift. The installation of the factory-roll-
formed metal roof system, along with trim, curbs, flashing and a final layer of insulation, took a crew of five men 12 days. The crew also was responsible for setting sensors for the Oak Ridge National Labora- tory data-acquisition system and adjust- ing solar purlins for the solar-thermal