FedEx Forum Project: Flexible duct wrap system vs. gypsum shaft wall construction
By Sarah Brewer

Any building project with FedEx in its name has to be on time.  But on-time, on-budget community centers were something that the city of Memphis, Tennessee had rarely experienced.  So the construction of the new FedEx Forum in Memphis was a challenge that the architects, contractors and city officials were determined to meet.  The arena, designed by leading sports architecture and engineering firm, Ellerbe Becket, is the new home of the NBA’s Memphis Grizzlies and it had to be completed for the start of the Grizzlies 2004-2005 season.  Formal ground breaking for the arena occurred in June 2002, and structural steel began to be installed in March 2003.  Interior work, such as grease ducts and insulation, needed to be completed before the grand opening of the arena in September 2004.

The $250 million FedEx Forum features over 800,000 square feet of facility space and seats 18,200 spectators on five levels for basketball.  It also hosts events ranging from concerts and hockey to exhibitions, family shows, rodeos and indoor motorsports.  The arena offers many amenities including a 260-seat club restaurant, an 8,600 square foot club lounge, a 200-seat event level restaurant, a sports bar with exterior patio seating, and food concession areas throughout the facility. 

To protect these extensive food service areas from potential fire, and to meet the project’s time and cost requirements, the insulation contractor, BP Mechanical Insulation, LLC of Memphis chose a flexible high temperature duct wrap system instead of constructing a traditional shaftwall enclosure around the arena’s ductwork.  The use of this type of insulation was just one of a number of innovative construction and installation processes used on the FedEx Forum project to keep it moving forward on a cost- and time-efficient schedule.

Thinnest, lightest duct wrap system saves weight, space and labor
The duct wrap insulation used in the FedEx Forum project is a new, optimized single-layer flexible enclosure for 1- and 2-hour fire rated kitchen exhaust ducts and chemical fume exhaust duct s.  The slim, compact design (1.5” thickness, 6 pcf density) offers the lightest system available and results in significant weight, space and labor savings when compared to traditional gypsum shaft walls or competitive wrap systems.  The system consists of a high temperature core insulation blanket completely encapsulated in an aluminum foil fiberglass reinforced scrim covering.  The core material is made from a calcia, magnesia, silica chemistry designed to enhance biosolubility.  The scrim provides additional handling strength and protection from grease and moisture absorption and tearing.

The duct wrap insulation’s ease of installation allowed BP Mechanical Insulation to stay on budget and meet project deadlines even after devastating windstorms in July 2003 caused all work on the project to be halted for two weeks.  Installation of the food service equipment began in February 2004, and BP Mechanical Insulation worked hand-in-hand with Memphis insulation distributor, F.S. Sperry Co. to ensure just-in-time delivery to the jobsite.  “The food concession areas were located throughout the arena and the kitchen duct work required quick installation often on very short notice”, comments Paul Fryman, Sales Engineer at F.S. Sperry Co.  “We had the insulation available for immediate jobsite delivery in the quantity required for each specific phase of the construction.”  In addition, BP Mechanical Insulation was able to offer a reduction on their insulation bid to the mechanical contractor when the single-layer duct wrap system was used to protect the kitchen exhaust ducts in place of the specified 3” calcium silicate board systems.  “The savings is significant due to the reduced labor required to install the wrap system versus the rigid board system”, says Lee Powell, co-owner with Mike Bell at BP Mechanical Insulation.  “Savings can be as much as 80% and we won this contract and others using the duct wrap system where we would not have been competitive with a board system.”

The BP Mechanical Insulation team needed to install the flexible duct wrap in all of the food service areas as quickly as possible.  In many of these places there was no room to enclose the ducts with a traditional gypsum board that requires a minimum of 6” air clearance around the chase.  The installation advantages were even more apparent in confined spaces where grease ducts were near concrete structural components, wall framing, plumbing and air ducts.

Another installation advantage of the flexible duct wrap system is a new vertical installation technique that saved BP Mechanical Insulation even more handling time.  For vertical duct runs, the insulation was applied in a continuous length parallel to the vertical length of the duct, instead of wrapping around the duct.

Installation of the duct insulation in all food service and other designated areas of the FedEx Forum was completed on budget and on time for the arena’s grand opening events in September 2004.

• Attractive alternative to gypsum board or calcium silicate board shaft enclosures that is lightweight, saves space and does not require added duct supports.
• Design flexibility in areas in close proximity to other service areas or combustible surfaces, or in areas with limited access.
• High temperature core insulation blanket is superior, non-combustible insulation able to withstand fire conditions.
• Meets national Mechanical Code requirements for protection of commercial kitchen grease exhaust ducts.
• Listed with independent fire test laboratories that confirm fire performance and required installation details.

The thin, single-layer, flexible duct wrap system that contributed to the on-time, on-budget FedEx Forum project is an ideal solution for many new construction projects such as stadiums, prisons, schools and hospitals.  It is a new technology which provides architects, engineers, and insulation contractors with a tested, low cost, and simple solution for providing fire ratings for kitchen exhaust ducts, as well as HVAC ducts, hazardous fume exhaust ducts, dryer vent exhaust ducts, toilet exhaust ducts, and refuse and linen chutes.

Sarah Brewer is Group Product Manager with Unifrax Corporation, Niagara Falls, NY.  She has been with Unifrax for 20 years with experience in application engineering and project management, with marketing responsibility for a number of passive fire protection product lines.  Sarah is active in codes and standards development; she is a member of the ASTM E05 Fire Standards Subcommittee, NFPA, Society of Fire Protection Engineers (SFPE) and the UL STP: UL 1978 Standards Technical Panel .  For more information on Unifrax, visit www.unifrax.com.
Reed Gnos, CSI is the area technical sales representative for Unifrax. Reed is with RPG Sales, Inc. Reed, a CSI member since 2004, is also Co-Chair of our chapter’s Certification Committee.