Re-Roofing / Retrofit roof applications are essential for commercial builders.
Roofing recovery is a process used on many commercial building re-roofs. In this process the existing roofing membrane is left is place. Any large pieces of debris are removed, a recover board is typically mechanically attached to the structural deck and a new roofing membrane is installed on top of the recover board.
This process has many benefits. From an environmental standpoint, leaving the existing membrane in place reduces the amount of waste material sent to the landfill. It also can increase the energy efficiency of the building by leaving existing insulation in place while adding additional insulation. For the building occupants, it reduces the disruption to normal building operations since no tear-off is required.
One concern with this process is that the existing roofing system most likely contains some amount of moisture, since the roof is not normally replaced unless there have been a history of roof leaks.
Extruded polystyrene foam (XPS) makes an ideal roofing recovery product. The manufacturers of XPS offer a wide variety of products for use in this application, including fan-fold products specifically designed for quick installation. The fanfold products have a variety of facers designed to work with specific membrane types. They also offer board-stock products designed for use under all single-ply roofing membrane systems.
Akron Civic Theatre, Akron, OH
The Akron Civic Theatre in Akron, Ohio, was designed by John Eberson and built in 1929 at a cost of $2,000,000. It stands as a historic reminder of the elegant Loew’s theater chain and is one of only five remaining “atmospheric theatres” in the United States. It is listed in the National Historic Register.
Once a plush entertainment center, the 2700-seat theatre offered films and vaudeville acts in the 1930’s bringing thousands of people to downtown Akron. Following World War II into the fifties, the Civic suffered a period of minimal use and fell into a steady pattern of deterioration. By the mid-1960’s the wreckers ball was poised to swing. In 1965 the first effort to save the Civic was undertaken, and from this initial aid a series of fund raisings and restorations has taken place culminating in 1987 in a community-wide capital restoration and endowment campaign of $2.8 million. The theatre’s final restoration is now underway and upon completion this marvelous public hall with its rococo décor is sure to recapture the splendor of its earlier days and, at the same time, spark redevelopment plans for downtown Akron over the next several years. Happily, UCI (now Owens Corning’s Specialty Foam Division) was able to play a rather significant role in this restoration project.
One of the first steps taken in the final restoration of the Civic was the replacement of the roof to preserve prior and ongoing restoration work. The reroofing project involved six separate areas totaling 28,000 square feet: outer lobby, grand lobby, auditorium, stage house, offices and south annex. Neither insulation nor weather resistive toppings such as gravel had been used on the original roof. In preparing the old roof, covering materials were completely removed down to the gypsum plank deck in order to reduce weight, remove accumulated moisture, and ensure the quality of the gypsum deck which was to remain in place.
The architect for the project, Rasmussen Design Group of Akron, Ohio chose a single ply roofing assembly consisting of the existing 3” gypsum deck, 1½” thick, 2’ by 8’ XPS TYPE IV as listed in ASTM C 578 2002 extruded polystyrene insulation, ½” wood fiber board mechanically attached to the gypsum deck with 4” fasteners (allowing for a minimum 2” penetration into the deck), and 2 ¾” square galvanized steel washers. The fasteners used had large threads to distribute wind uplift loads over an area compatible with the strength of the deck. An EPDM single ply membrane was adhered to the ½” wood fiber substrate. While XPS TYPE IV as listed in ASTM C 578 2002 was included in the new roof to help reduce high heating bills for the old theatre, the thickness was limited by the length of fasteners used to attach the single ply system substrate to the gypsum deck. “XPS insulation was chosen because of its strength and high R-value of 5 per inch of thickness,” said Joe Herdna of Branch Roofing, Akron, roofing contractor for the project. Also considered was XPS’s ease of installation and long term insulating performance.
The entire roof replacement was completed in May 1988. The Akron Civic Theatre is now delighting its patrons once again.