FPEeXTRAIssue36

Construction Fire Safety

 

By Keith Flanders, PE

The building construction industry has recently generated a number of unfortunate headlines due to fires that occurred in wood-framed buildings. While discussions about the overall safety of wood construction may continue, measures for protection during construction can be implemented immediately to reduce the risk of these events occurring again.

According to the National Fire Protection Association (NFPA) , between 2010 and 2014, fire departments in the U.S. responded each year to an average of:

  • 3,750 fires in structures under construction,
  • 2,560 fires in structures undergoing major renovation and
  • 2,130 fires in structures being demolished.

The annual losses from such construction fires are estimated to cost hundreds of millions of dollars. Combustible wood buildings are generally safe once the building is complete, with all of the required fire protection features in place. However, these protection measures are not always active until the final days of construction. This leaves an extended time period in the construction process when a combustible building may be left unprotected.

Some of the main causes of such fires relate to cooking equipment, heating equipment or arson at a project site. Additional ignition sources to consider include torches or welding operations, smoking, and/or other exposure fires.

Fires during construction are not only detrimental to the building owners and contractors, but also affect others beyond the direct contributors. For example, firefighters are further exposed to the hazards of fighting a fire, and the consequences could be life-threatening. Occupants planning to move in must find alternative accommodations when construction projects are delayed as a result of such fires. Occupants of adjacent properties may also be displaced during such events, creating undue stress for the public. Insurance companies are also concerned with these fire hazards, which may increase premiums and lead to even-more¬–expensive properties, as if they were not already expensive enough.

Common-practice safety features for construction sites include providing portable fire extinguishers, exit signs and manual air horns for emergencies. Recent discussions in the construction industry have resulted in additional recommended protection measures to increase safety at work sites. These features are being considered for implementation on construction projects (if are not already in place):

  • Heat detection throughout and fire alarm notification
  • Dry sprinkler systems
  • Advanced site-security measures
  • Additional site inspections specifically for construction fire safety

Fire sprinkler systems are at the forefront of protecting buildings in today’s developing world. However, such systems are often not active until project construction is nearly complete. Accordingly, there has been a push to activate sprinkler systems as soon as possible on construction sites, whether by using a fully wet system after the system installation or a dry sprinkler system in cold environments until a heating system is in place. Construction teams may seek to use a pre-action system with heat detection to help prevent any accidental sprinkler activations. For renovated buildings with existing sprinkler systems being replaced, including a form of temporary heat detection is often recommended to maintain a level of protection while the sprinkler system is decommissioned.

When a standpipe is required for a building, it should be installed in progress with the building construction to aid in protecting the building. Standpipe systems are typically constructed in the stairs a few floors below the framing or assembly of the building, depending on the type of construction. The standpipe system must be of an approved type and include a readily accessible and identifiable fire department connection. These systems must be tested hydrostatically before being identified for use. The system may consist of a manual dry standpipe system, which can also be monitored by an air pressurization alarm system to ensure it is being adequately maintained. The local authority with jurisdiction should always be consulted about the type and arrangement of the standpipe system provided during construction.

Any such safeguards with respect to the fire protection systems should be discussed with the local fire department and other authorities with jurisdiction (i.e., water department) before implementation. This helps ensure the proper means and methods are used in installing these systems and prevents other potential issues.

In accordance with NFPA 1, Fire Code, procedures must be implemented to safeguard construction sites for life safety and property protection. The precise requirements for such protection are not necessarily prescribed, since each and every project is unique and offers challenges that may have to be accounted for specifically. However, NFPA 241, Standard for Safeguarding Construction, Alteration and Demolition Operations, offers guidance on ways to implement such a plan and should be referenced for any construction project.

Construction fire safety plans should be created anytime a construction, alteration or demolition permit is necessary. Even smaller projects can affect means of egress or create an undue fire risk that can result in unnecessary losses. Preparing a construction fire safety plan helps protect construction personnel, building occupants, adjacent buildings and first responders from the risks associated with such operations.

A construction fire safety plan is ultimately the property owner’s responsibility; however, responsibility for compliance may be delegated to a contractor performing the work. The specifics of a construction fire safety plan may be written by the owner, contractor, engineer or other qualified individual who is intimately involved with the details of the project. Such individuals should understand the construction logistics, associated hazards and required mitigation that are necessary to alleviate the risk of fire.

The construction fire safety plan should identify a Fire Protection Program Manager (FPPM) who is knowledgeable about the project scope and fire protection/life safety-related matters. The FPPM should be on site and an assistant FPPM should be designated in their absence.

The complexity and length of the NFPA 241 Plan will vary depending on the size and complexity of the project. A high-level summary of what NFPA 241 Plans may address includes the following:

  • Applicable Codes
  • Responsible Parties and Roles
  • Fire Safety Approach
  • Hazards and Proposed Mitigation
  • Pre-Fire Site Plan
  • Logs and Inspection Forms
  • Impairment Plan
  • Evacuation Procedures
  • Training
  • Hot Work
  • Temporary Construction (i.e., Construction Offices, Trailers and/or Storage Sheds)
  • Equipment with Internal Combustion Engines
  • Heating Equipment
  • Smoking
  • Waste Disposal and Trash Chutes
  • Flammable and Combustible Liquids
  • Temporary Electrical Service
  • Security
  • Combustible Material

Specific impairments that may have to be considered during a construction project include:

  • Sprinkler system shutdown
  • Smoke detector disabling
  • Elevator recall smoke detector disabling
  • Blocking, reducing or re-routing of means of egress
  • Standpipe system shutdown
  • Removal of drop ceiling resulting in sprinkler system impairment
  • Smoke control system shutdown/maintenance

The progress of construction is always changing the way fire protection may be provided to a structure. Accordingly, any plan to protect a project must also be adaptable to the varying conditions. This is a difficult aspect to manage and often requires constant oversight to verify that all protection features remain in place throughout the project. To help manage this, construction sites must maintain good housekeeping practices to help reduce the hazards presented on site. This includes demolition projects which often entails the accumulation of combustible debris that requires consideration and removal on a regular basis.

Owners and contractors alike must continue to emphasize construction fire safety, which requires an approach that is more proactive than reactive. This includes developing a pre-fire plan to ensure the fire department has sufficient access and information when arriving on-site. On-site personnel must be briefed regularly about the importance of fire safety and how they can help mitigate the risk. It is also prudent to conduct regular walkthroughs of a construction site with the emphasis on fire safety, not just the progress of construction.

Consequently, construction fire safety continues to be an ever-evolving practice that must take into consideration the value added by particular protection measures, compared to the overall cost added to a construction project. The risk of construction fires is omnipresent and can lead to catastrophic events, needlessly risking the lives and general welfare of firefighters, construction workers and the public.

Keith Flanders, PE is with Cosentini Associates.


References

Campbell, R. (2017, April). Fires in Structures Under Construction, Undergoing Major Renovation, or Being Demolished. National Fire Protection Association. Quincy, MA.