By Gregory Havel
Last month’s Construction Concerns article on fire doors dscussed the performance of a vertical rolling fire door under actual fire conditions, without the support of either an automatic fire sprinkler system or a fire department handline. The fire door in the photos had been installed decades ago and relied on fusible links to hold the door open and to release it under conditions of fire or extreme heat.
In most jurisdictions, fire doors are installed in compliance with NFPA 80, Fire Doors and Other Opening Protectives, 2013 edition, and NFPA 72, National Fire Alarm and Signaling Code, 2013 edition. Although fusible links are a proven and reliable technology, today’s codes require and permit the use of more sophisticated technology to release fire doors.
Fire-rated door and frame assemblies are required in openings in fire-rated division walls in any type of construction. Where large openings are required as in commercial and industrial buildings, they are often protected by vertical rolling fire doors. These doors are made of interlocking metal slats that are stored rolled up in an enclosure above the doorway, with guide tracks on each side that hold the door when it is closed. These doors are operated by gravity and may be counterbalanced by springs. They are normally held open by mechanical devices that release the door to close when a fusible link melts. They can also be set up to be released by smoke detectors or by fire alarm system activation.
Photo 1 shows a doorway between the customer area and the service area of a large auto dealership. This doorway is eight feet [2.438 meters (m)] high × 12 feet (3.657 m) wide.
(1) Photos by author.
The release mechanism for this door has three fusible links connected in series. One is at the top center of the rollup enclosure (photo 2), attached to its chains with s-hooks, with a turnbuckle to adjust chain tension. The others are in the chain between the red lever at the left side of the door and the red control box (photo 3), with the chain tension controlled by a turnbuckle.
When the installation is complete, this door will be arranged so that release of the door by fusible links will activate the fire alarm system and so that activation of the fire alarm system by smoke detector, heat detector, manual pull station, or the automatic sprinkler system will close the door.
After this type of door is release and closed, it can be raised from the inside with a manually-operated chain-drive device. The easiest access is to go around the closed fire door through a swinging service door.
If one of these vertical rolling fire doors is opened manually, it could close again by gravity if it is not blocked properly, isolate interior fire attack teams, and cut off their water supply. If the door is blocked open or if an inverted “V” cut is made in the center of the door, the opening in the fire-rated wall is no longer protected, and it will require a large handline and a team of firefighters to prevent the fire from extending through the opening.
For more information, do an Internet search for “vertical rolling fire doors,” review the chapters on fire-rated walls and doors in your building construction textbook, and review NFPA 72 and 80, 2013 editions.
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Gregory Havel is a member of the Town of Burlington (WI) Fire Department; retired deputy chief and training officer; and a 35-year veteran of the fire service. He is a Wisconsin-certified fire instructor II, fire officer II, and fire inspector; an adjunct instructor in fire service programs at Gateway Technical College; and safety director for Scherrer Construction Co., Inc. Havel has a bachelor’s degree from St. Norbert College; has more than 35 years of experience in facilities management and building construction; and has presented classes at FDIC.
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