Construction Site Fires: The Sprinkler System Dilemma

Firefighters use multiple elevated streams during a fire in Rockville, Maryland.
Firefighters use multiple elevated streams during a 2014 fire at a large building under construction in Rockville, Maryland. Photo courtesy Pete Piringer, Chief Spokesperson for Montgomery County (MD) Fire & Rescue Service.

By Raymond O’Brocki

In August 2020, fire tore through an 88-unit apartment building under construction in Somerville, New Jersey. The fire appears to have started in the attic space and spread quickly. Somerville Fire Chief Brian Iselin stated that first-arriving units responded quickly and established a reliable water supply, but flames were already through the roof. The fire resulted in a $16 million loss and disruption to the New Jersey rail line into New York City.[1]

A seven-story, multi-family mixed use structure, called “The Fuse,” caught fire in College Park, Maryland in 2017. It caused $39 million in damage and closed the University of Maryland for an entire day. College Park Fire Chief Bill Corrigan said units arrived quickly but the “fire burned much longer than it should have.”[2]

In Rockville, Maryland, an apartment building under construction in 2014 caught fire because a kerosene heater used to cure concrete ignited combustible waste and quickly spread into the roof. The 150-unit complex was just weeks away from occupancy. Former Montgomery County Fire Chief Stephen Lohr stated that units were on the scene quickly and had an adequate water supply. The fire caused Interstate 270, a major artery into Washington, D.C., to be shut down. The fire resulted in a $15-20 million loss.[3]


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These fires shared many similarities. All three fires occurred in multi-family dwellings that were under active construction when the fire started and nearing completion. Each fire resulted in a total loss of the respective building and caused a major disruption for the community. The building envelopes were complete, the buildings were conditioned, and there was a water supply for the sprinkler system either tied into the building or nearby. However, there was one likeness that may have caused the fire to grow out of control when it could have been easily suppressed. These construction sites had fully functional sprinkler systems–but the systems were not turned on.

The Three-Legged Stool of Construction Site Fire Suppression

The three-legged stool of effectively suppressing construction site fires is:

  • Early Notification
  • Adequate Water Supply
  • Fire Department Access

Responding units must have all three or the stool will not stand. An adequate water supply is useless if the fire department has no access to fight the fire. Early notification does no good if there is not an ample water supply. Fire department access is of no help if the fire is already through the roof!

In each of these cases, firefighters had an adequate water supply when fighting the construction fires in Somerville, College Park, and Rockville. The responding units did not report any unusual fire department access issues, the fires were reported early, and units arrived quickly. The fire departments did everything right and still the three properties were a total loss.

Sprinkler Systems During Construction

In the College Park fire, Channel 4 Washington reported that the building’s “fire sprinkler system had already been installed, but the current code did not require it to be turned on yet, since the building was still under construction.” Chief Corrigan stated: “This would have been a one sprinkler head fire, and the next day nobody would even have been talking about this incident.”[4]

One recurring theme in many construction fires is the presence of a sprinkler system that is not turned on. There are rational reasons to not turn on the sprinkler system before the system is approved and the building is occupied. Before the sprinkler system is tied into the fire alarm, the system is unsupervised and if an accidental discharge occurs it could go undetected for hours, doing considerable water damage. In cold climates when the building envelope is not complete or the structure is unconditioned, the pipes can freeze and burst.

The National Fire Sprinkler Association (NFSA) has no official position on the subject. But NFSA’s Jeff Hugo, Vice President of Codes, Standards, and Public Fire Protection, says:

The standard fire sprinkler contractors design and install to, NFPA 13 and 13R, is for occupied buildings, after construction. A system under construction, is that, under construction and making progress each day, but also is susceptible to damage from other trades and weather. There is not a construction fire protection system standard available. If there are local ordinances that alter IFC Chapter 33 and NFPA 241 for construction fire protection, it is better our contractors to know up front, so they can bid it and be ready each day to have a system ready with the valve on at the end of the shift. When construction fire protection plans are in the bid, contract, and construction process, there must be protocols and project objectives in place for the project manager, owner, and contractors to follow. It is important to recognize that a fire protection system under construction does not have the same level of protection during construction as it has when completed. As walls are installed, piping is routed, and construction materials are staged every day, the construction fire protection scheme changes. It is important to safeguard the fire protection contractor during this process and recognize the systems are long from being accepted, approved, commissioned, or supervised.[5]

Jeff Hugo touches on an important but sometimes overlooked point. There is no standard for the design and installation of a sprinkler system in a structure under construction. He stresses that it’s just “not as easy as turning a valve on or off.” A sprinkler system is designed and installed with the assumption that it will be used in a finished building with predictable fuel loads. How would a sprinkler head respond to a fire when the hard ceiling is not installed? How would placement and spacing of sprinkler heads be affected by exposed stud walls and ceilings?

Construction fire safety consultant Robert Neale of Integra Code Consultants thinks that industry leaders should look to solve the problems involved with turning on a sprinkler system early. He says: “There are few practical limits why sprinklers couldn’t be operational during construction – as long as the pipe is protected from thermal damage and the system is capped off in a way that water wouldn’t flow out an open orifice. After all we require temporary standpipes during construction, why not properly designed and installed sprinklers? Perhaps some industry representatives could get together and propose a national standard for temporary sprinkler system criteria for protecting buildings during construction.”[6]

Rob Neale brings up the idea of a temporary sprinkler system, not simply turning on the permanent system once it is complete or as it progresses. A temporary system may be cost prohibitive. However, the cost might be mitigated if it could be dismantled and taken from job to job. Another less expensive approach may be to oversize some components of a typical sprinkler system to address unique fire loads associated with the construction phase.

Developer’s Perspective

Jeff Hutchens, who is the former Safety Director for global builder Avalon Bay, isn’t as optimistic regarding turning on sprinklers early or using a temporary system to curb construction fires. When asked about the subject Hutchens stated: “I’m presuming you are discussing the potential to install and energize sprinkler systems sooner in the building process as a protective feature – to protect wood frame structures under construction. Bottom line is this approach is a non-starter.” He sees many practical and technical hurdles to overcome before this approach could be viable. He listed the challenges as such:

  1. Risk management and insurance carriers concerned with high potential for inadvertent activation causing significant water damage.
  2. How to get water from the street to the system if the supply piping is not yet installed.
  3. Keeping the water supply from freezing.
  4. How to get water through system when the pumps have not been installed/powered.
  5. General contractors often allow temporary heat systems to increase temperatures inside the building to exceed 130°F, which would trigger a system activation without a real fire present.
  6. Pump rooms are not fitted out until later in schedule, often because piping/system design is “in progress,” “code review” cycle, or “pump(s) on order.”
  7. Likely damage to sprinkler heads by other trades (why they are installed near conclusion of project after the finish trades are nearly complete).
  8. Overhead void areas on multi-family homes are filled with HVAC, data, and electrical systems – the risk of damaging sprinkler piping while installing these other systems is significant (and no space is available to install a “temporary loop.”)
  9. Moving pipe to accommodate drywall or covering is hard for painting.
  10. If a temporary system does not activate in the event of a fire, whose insurance covers losses?
  11. If a temporary system activates without a fire, whose insurance covers losses?
  12. General contractors need to rethink temporary heat, which will increase cost and affect schedule.
  13. More than half of these fires are arson. Would a temporary sprinkler system address intentional fires?

But Hutchens didn’t completely shut out the idea of a temporary system. “One could design a skid mounted [portable power, portable pump] water mover to be combined with a temporary [removeable] loop system. Link the power/pump to some remote sensors and you have a semi-automatic temporary system. The skid is reusable. The technology isn’t rocket science. More about taking the risk – most developers and builders don’t believe that a fire could happen to them.”[7]

Fire Service Viewpoint

Some jurisdictions require that sprinklers be activated as soon as possible. Boston, Massachusetts, is one of those jurisdictions. Boston Fire Commissioner Jack Dempsey speaks about the challenges his department faces when enforcing this requirement:

In Boston, we require sprinklers to be installed and operational at the soonest possible time. Weather can play a big part in the timing of this when freezing temps could cause large problems. Contractors often don’t want to take care while working around sprinklers in case of accidentally tripping a head. There can be a lot of give on both the construction end and the fire department end when working out a plan that works for both. Each job has obstacles that need to be worked out but, in the end, when there is no one on site and a fire starts the sprinklers can save the day. Would you sacrifice a little water damage to save the whole job?[8]

Commissioner Dempsey has chosen to partner with the contractors to work out an agreement to when is the best time to energize the sprinkler system prior to the certificate of occupancy and the commissioning of the system.[9]

The City of Los Angeles (CA) Fire Department has created a standard for Fire Safety at Construction Sites in their Fire Prevention & Public Safety Bureau “Requirement #7.” Section D, Subsection 4, Sprinkler Systems requirement:

Fire Sprinkler Systems: Where fire walls are not provided and automatic fire sprinkler systems are required to be installed in the building being constructed, the fire sprinkler system shall be placed in service as soon possible. For buildings of Type I or II non-combustible construction, activation of the fire sprinkler system may
be delayed until combustible finishes, furnishings or equipment are installed, and the building or area is not used for combustible storage or any other purpose.

Immediately upon the completion of sprinkler pipe installation on each floor level, the piping shall be hydrostatically tested and inspected. After inspection approval from the Department of Building and Safety, each floor level of sprinkler piping shall be connected to the system supply riser and placed into service with all sprinkler heads uncovered. Protective caps may be installed on the active sprinklers during the installation of drywall, texturing, and painting, but shall be removed immediately after this work is completed.

For system activation notification, one exterior approved audible device, located on the exterior of the building in an approved location, shall be connected to each automatic sprinkler system water flow device prior to installation of the monitoring system. Such sprinkler water-flow alarm devices shall be activated by water flow equivalent to the flow of a single sprinkler of the smallest orifice size installed in the system. For buildings equipped with fire sprinkler systems that are undergoing alterations, the sprinkler system(s) shall remain in service at all times except when system modifications are necessary. Fire sprinkler systems undergoing modifications shall be returned to service at the end of each workday unless otherwise approved by the Fire Department. The General contractor or his/her designee shall check the sprinkler control valve(s) at the end of each workday to confirm that the system has been restored to service.[10]

The city requires, among other things, that the sprinkler system be tied into a fire alarm, to provide early notification of water flow. This solves the unsupervised sprinkler system problem. It also requires that the sprinkler system be tested and inspected as each floor level is completed. This may be burdensome to sprinkler contractors and inspectors alike.

West Des Moines (IA) Fire Marshal Mike Whitsell reports on their sprinkler requirement during construction, they have a different approach that solves the freezing pipe issue:

We have had excellent success in working with our local sprinkler contractors and building contractors in West Des Moines to have dry attic sprinkler systems connected very early in the building construction process to temporary fire department connections (FDCs) that our firefighters can connect to and supply with water during a fire. Most sprinkler installations start from the attic down during the construction process, so the infrastructure is in place early on. And while the city water supply isn’t yet connected to the system, hydrants are active, so our fire trucks become the sprinkler riser for the sprinkler systems. All that’s left is working with the sprinkler contractor on the best location for a temporary FDC and you have another tool in the toolbox available to use.[11]

Deputy Chief Whitsell crafted this requirement in the wake of a devasting retirement residence construction site fire in April 2020. As he watched the fire rage, he could see the sprinkler piping and attic sprinkler heads through the flames as the fire burned around them. He said: “It was a sickening sight to say the least. I look at this as an added, inexpensive layer of protection during construction when buildings are most vulnerable. While this process may not extinguish a well-advanced fire, I strongly believe it will help.”[12]

Christopher G. Towski, Construction Fire Safety Compliance Officer for the Cambridge (MA) Fire Department believes that the active fire protection such as a sprinkler system should be installed in conjunction with passive fire protection. “From a firefighting standpoint, the concept of early water is an obvious key to rapid suppression control and extinguishment. This concept could work very well for construction that is taking place in a building that is already erected with other fire protection passive and active features such as enclosed walls and smoke detection.”[13]


There are differing opinions on the efficacy and practicability of activating a sprinkler system early. It is clear there is no “one-size-fits-all” solution. Each jurisdiction that contemplates involving sprinklers as a solution to the construction site fire issue will have to tailor it to their local conditions.

There is little doubt that the presence of a working sprinkler system in any of the structure fires mentioned here would have controlled or extinguished the fire. But all these structures were nearly completed and weeks away from occupancy. Many construction fires occur much earlier in the construction process. How would these structures be protected with a sprinkler system?

Using a sprinkler system to protect property under construction presents technical and practical challenges. Good fire prevention practices, including a solid site safety plan that is well executed, is still the best approach. Although there is no easy answer to the “sprinkler system dilemma” regarding construction fire safety, it is still important to ask the questions and seek solutions.


(1) Deak, Mike, Somerville fire: Cause still unknown in $16 million apartment building blaze, Retrieved from August 24, 2020

(2) Stably, Matthew, Fire Chief: Closed Valves, Limited Access, and Size and Type of Construction Hindered Response to 5-Alarm College Park Fire, retrieved from August 18, 2017.

(3) Channel 4 Washington, Crews Battle Massive 3-Alarm Fire in Rockville , retrieved from, Published April 1, 2014, Updated on April 2, 2014 at 6:51 pm     

(4) Ibid

(5) Jeff Hugo. Private correspondence.

(6) Robert Neale. Private correspondence.

(7) Jeff Hutchens. Private correspondence.

(8) John Dempsey. Private correspondence.

(9) Ibid.

(10) Los Angeles Fire Prevention & Public Safety Bureau, Requirement #7: Fire Safety at Construction Sites, retrieved from Revised 1/23/2020.

(11) Mike Whitsell. Private correspondence.

(12) Ibid.

(13) Christopher G. Towski. Private correspondence.

Raymond O’Brocki, CBO, is the manager of fire service relations for the American Wood Council. He was the chief building official for Rockville, Maryland. O’Brocki was appointed the fire marshal for Baltimore in 2008 and served as the assistant chief with the Baltimore (MD) Fire Department until retiring in 2013. He served on the Maryland State Fire Code Update Committee, the steering committee for the Mid-Atlantic Life Safety Conference, and the National Fire Protection Association’s (NFPA’s) Urban Fire Safety Task Force and is on the NFPA 1, Fire Code, Technical Committee. He is the administrator of the Construction Fire Safety Coalition, a graduate of the University of Baltimore School of Law, and a licensed attorney.


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