By Gregory Havel
The “engineered steel building” was designed as an inexpensive, lightweight, and noncombustible substitute for structures of other building code types including wood frame (type V), heavy timber or mill (type IV), ordinary or brick-and-joist (type III), and the more typical noncombustible (type II) building. Although they have sometimes been considered temporary structures when compared to conventional construction, with proper care these buildings have a life expectancy of more than 50 years.
Because of their construction materials and methods, they are usually limited to a single story, although mezzanines and second stories are sometimes included, which have structural supports independent of the enclosing engineered steel building.
Photo 1 shows one end of a partially completed engineered steel building. It shows several of the load-bearing column and beam assemblies that span the width of the building; vertical and horizontal intermediate structural members that support the roof and to which the steel wall panels are attached; the fiberglass batt insulation in the wall; the steel liner panel on the inside of the wall at the left; and the edge of a mezzanine, visible through window and door openings that makes this end of the building two stories.
(1) Photos by author.
Photo 2 shows the connection between a column and roof beam, with the broad “haunch” at the joint, which redistributes the downward and outward thrust of the pitched roof into a downward load on the foundation. Horizontal members to which wall panels will be attached as well as others that will support the roof are also visible.
Photo 3 shows the underside of the roof after it is installed on top of batt insulation faced with a plastic vapor barrier.
Photo 4 shows an alternate method of construction, which uses interlocking double-sided steel panels filled with foam insulation in place of the metal exterior panel as well as a liner panel with fiberglass batts in between.
Today’s engineered steel buildings can be very large, covering several acres under one roof (1 acre = 43,560 square feet = 0.405 hectares) with clear spans between rows of columns greater than 100 feet (30.5 m).
Photos 5, 6, and 7 show a municipal sports complex under construction that, when complete, will include inside the building a competition-sized hockey and ice-skating rink; a gymnasium for basketball and other activities; tennis courts; a soccer field; and all of the offices, locker rooms, storage spaces, and meeting rooms needed to support the activities of hundreds of people in the building at the same time.
In photo 7 on the left side, the framing of the building is nearly complete and in the background. Additional sections of roof girders will be attached to the beams that extend from the columns and which will extend to the next line of columns to provide the clear span needed for the indoor soccer field.
Because of the large number of people who can be present at any time, and because of the combustible nature of the building’s finishes (i.e., combustible artificial turf, combustible floors of wood or polyurethane foam, wood bleacher seating, and the clothing and duffel bags brought by the building’s occupants), buildings like these are usually protected by a National Fire Protection Association 13, Standard for the Installation of Sprinkler Systems, -compliant automatic fire sprinkler system.
Because of the size and complexity of this kind of facility, the fire sprinkler system will have several risers and may have a fire pump, depending on the water supply in the neighborhood.
Although a sports complex like the one shown in these photos will not have as great a fire load inside the building as a big box home improvement store or a mega-mart, it is likely to have a much larger population of athletes and spectators. A facility like this needs a detailed preincident plan that is updated regularly to cover changes in occupancy and activities.
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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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