Construction Concerns: Construction Job Site Hazards

By Gregory Havel

Most of the training that firefighters receive in building construction deals with the completed building. However, to arrive at the building about which we have been taught, we must develop the building from a vacant lot to the final product by a process usually known as construction.

Buildings of any type, for any type of occupancy, that are under construction will have some of the following common characteristics:

  • Fire-resistive components of the structure may not yet be in place including gypsum drywall board, firestopping, and fire-caulk.
  • Standpipe and automatic fire sprinkler systems may be incomplete and not available for firefighter use.
  • Construction may use processes and products that may not be permitted in the completed building without special procedures and permits including welding, use of torches for cutting and soldering, grinding, and use of solvents and solvent-based materials.
  • Incomplete parts of the structure can provide trip and fall and entrapment hazards for firefighters.
  • Permanent parts of the structure including stairways, smoke-operated doors, and “fire doors” may not be in place and ready for use.

A fire department’s response to a building under construction will evolve more rapidly and be a very different type of fire than it would have been in the completed structure.

Photo 1 shows a code Type II (non-combustible) building under construction. The mezzanine has a wood guardrail that complies with OSHA’s 29 CFR 1926 Subpart M Fall Protection: 1926.502 (b). (OSHA’s regulations are available at The permanent guardrail will be made of steel and meet or exceed the same requirements. The construction ladder in the photo will be replaced by a steel and concrete stairway for permanent access to the mechanical equipment and storage areas on this mezzanine.

(1) Photos by author.


Please note that if the incident requires firefighter access to a level served only by a construction ladder, it should be replaced for the duration of the incident by a fire service ladder, which is designed for greater capacity and greater safety factor than a construction ladder.

Photo 2 shows a code Type II (non-combustible) building under construction. This floor has an opening for ductwork that has been covered as required by OSHA’s 29 CFR 1926 Subpart M Fall Protection: 1926.500 (b) and 1926.502 (i). For a temporary closure, the oriented strand board (OSB) cover as shown is considered adequate, although it is combustible. After the ductwork is installed, the space left between the concrete floor and the steel ductwork will be closed with firestopping, fire caulk, or other fire-resistive material. If this opening were larger, it would probably be surrounded by a guardrail until the ductwork was installed, rather than equipped with a hole cover.



Photo 3 shows the open cores in concrete masonry units against which a concrete floor has been poured. By OSHA’s definition, a hole requiring a cover is two inches or more in its least dimension (29 CFR 1926.500 (b)). Although these holes are not large enough to drop a firefighter through the floor to a lower level, they are large enough to provide a trip hazard, to trap the toes or heels of fireboots, and to interfere with the movement of wheeled equipment, hose, and other equipment. The cover was removed from these openings so that they could be photographed.



Photo 4 shows trenches that have been sawn in the concrete floor of a building during remodeling, for the installation of new plumbing. Since it is impractical to install long lengths of pipe in narrow, shallow trenches that have temporary covers, plumbers frequently omit the covers and use barricade tape to isolate the work and hazard area. After the trenches are dug, the pipe is installed, pressure-tested, and reviewed by the plumbing inspector; the trenches are then closed with compacted granular fill. These trenches are ready to be filled with concrete to match the existing floor level. Although these trenches will not drop a firefighter to a lower floor level, they provide a trip hazard, can trap fireboots, and interfere with the movement of wheeled equipment, firehose, and other equipment.



If there is a fire in any of these buildings under construction, and especially if the construction is code Type V (wood frame), expect a fire that expands rapidly, and extends quickly between floors and other areas of the building. In a wood frame building, the fire may quickly grow beyond the ability of the fire department to extinguish, limiting its activities to exposure protection. An example of this type of fire was the Ybor City Fire in Tampa, Florida, on May 19, 2000. The fire was discussed in the October 2000 issue (Volume 153, Issue 10) of Fire Engineering in an article by Scott Ehlers, Leslie P. Ennis, and Emilio F. Salabarria. See the article at

Firefighters must pay attention to construction job sites, whether new construction or remodeling of existing buildings. Periodic tours of these locations are essential, with summaries of the status of the construction and fire protection systems provided to all personnel who were unable to participate. These locations are a good place to learn about building construction. Many contractors will arrange tours for emergency service personnel if requested, and fire department training officers can discuss with the tour participants the anticipated fire behavior in the structure in its current condition.

The periodic presence of firefighters at construction job sites as a learning experience (not just for code enforcement) can be an incentive for the contractors to police their areas so that they are always presentable and relatively hazard-free.

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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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