Firefighting Challenges in Converted Mills


In old mill buildings, a structure’s rehabilitation and change of occupancy can present a challenge. In the decades before 1900, mill buildings of varying sizes began to appear in the heavily industrialized areas of the United States. Many of these mammoth structures filled entire city blocks; some even had their own self-supporting villages outside city limits. Mill or Type IV (heavy timber) construction, according to National Fire Protection Association 5000, Building Construction and Safety Code, features, among other things, “interior structural members including columns, beams, girders, trusses, arches, floors, and roofs of solid or laminated wood without concealed spaces.” The structures had to be capable of holding heavy loads of manufacturing equipment and stock.

However, by the early 1980s, manufacturing processes had changed. Many companies retooled, moved to new facilities in industrial parks, transferred manufacturing overseas where labor was cheaper, or simply closed their plants altogether. The behemoths of our first industrial base began to close and decay.

Many of these structures sat idle for years, until housing markets improved, urban centers showed signs of rebirth, and small specialty manufacturers needed affordable work space. The makeover of mills for the 21st century is now in full swing. This recycling of century-old real estate poses many challenges for firefighters (photo 1).

(1) The large scale of mills dictates that makeover projects evolve in phases, usually over several years. A portion of a building may be occupied while major renovations are underway in other areas. (Photos by author.)



Among our first concerns are the original features of the mill construction era. The massive size of the buildings and potential fire load can overburden even the largest fire department’s resources. Since these early mills relied heavily on water power, they were almost always built alongside rivers, obstructing access to at least one side of the building.

Century-old construction means that there may be old neighborhoods with small municipal water mains and narrow streets, which may be mere alleys in some cases. Many of the oldest mills were constructed along swift-moving rivers outside what were then the city limits. This necessitated the building of “mill villages” surrounding the mill, containing many small multiple dwellings for the workers, a few “company stores,” and often a small church. Many of these structures may remain in various states of disrepair and become severe exposure hazards for any significant mill fire. Of course, the mill itself may have suffered the effects of long exposure to the effects of weather. No matter how well the main structural components are rehabbed, they are still 100 years old.


Mill makeovers may take many forms, but they involve changing the occupancy type from industrial or commercial to one of the following: residential, multitenant commercial/industrial, or mixed-use residential/retail/office. The large scale of mills usually means that makeover projects evolve in phases, usually over several years. A portion of this building may be occupied while major renovations are underway in other areas. Remember the added dangers of construction zones, such as voids between floors and open walls and shafts (photo 2).

(2) A fourth-floor opening to nowhere found on a mill makeover site.

Fire department involvement in these projects is crucial at all levels—from the fire prevention bureau down to the district companies—and should begin in the design phase and continue with regularly scheduled fire marshal and district fire company inspections. Although the marshals have a clear-cut agenda based on codes and plans, the companies protecting these buildings need to be familiar with demolition and renovation activities on the structure to update their tactical options as the building changes. Familiarity with construction methods will prove invaluable long after all the walls are boarded and the floor plan changes.

Our options, priorities, and challenges may change based on the structure’s changes in occupancy. Originally, these buildings were usually constructed for and occupied by a single manufacturing company. However, one of the first changes in use for these mammoth buildings involves cutting them up into multitenant occupancies. These subdivided mills can pose many tactical firefighting problems.

Often, the company that owns or manages the structure doesn’t have a physical presence on-site, which can make finding a responsible party difficult. Often the tenants don’t even have valid contact numbers for emergencies. Because mill space is generally less expensive to rent than space in modern industrial parks, some commercial tenants may be “fly by night” businesses that rent space, change floor plans, and divide up the original huge factory floors into much smaller spaces. They may create voids, eliminate exits, board up windows, and subdivide electrical service. Months later, they may fade away, one step ahead of municipal code enforcement, sometimes leaving hazardous waste from their operations in the deserted occupancy.


Even when a mill is occupied and managed by legitimate parties, access to each small workspace, added interior partitions that create voids, and a multitude of manufacturing processes on-site can interfere with our ability to force entry, stretch lines, find the fire, and operate safely. Such occupancies may include an industrial supply warehouse or involve industrial processes such as jewelry plating, industrial welding, or computer assembly. All of these businesses may be found on a single floor of a mill makeover.

Other changes of use may include a mix of residential units along with office or retail shops. In addition to the common hazards such as newly created voids and confusing floor plans, adding dwelling space greatly increases the life hazard. First-arriving companies may confront a fire involving several thousand square feet in the middle of a huge building that has been compartmentalized and may have hundreds of occupants. This is similar to confronting an average-sized private dwelling fully involved with attached exposures on all sides, as well as above and below. Additional challenges include long hose stretches; difficult access points; and newly created concealed voids, pipe chases, and HVAC systems (photos 3-6).

(3) A common corridor in a mill structure converted to condominiums. The conversion is below grade on the right side with the brick wall. These corridors will require long hose stretches and have limited access/egress points.


(4) Many makeovers include complex layouts with living spaces accessible only from remote points to make use of all parts of the existing structure.


(5) Original mill construction had no concealed void spaces.


(6) During makeovers, voids are commonly created to accommodate modern systems.


Project designers are usually eager to retain the original high ceilings and exposed heavy timbers for aesthetic reasons. Although this is a selling point for buyers looking for authenticity, the buttoned-up units with their energy-efficient windows and tightly sealed doors can retain serious amounts of heat and have great potential for flashover with their high ceilings. In some noncompliant renovations, firefighters may find new ceilings installed below the original exposed heavy timber construction. Note this condition, and immediately inform the proper code enforcement officials.

Some of these old buildings have been converted to public self-storage centers, which is quite easy for the property owners. With a ceiling height of 14 feet or higher, the lightweight corrugated steel and plastic storage dividers can be assembled easily with plenty of extra overhead room. Loading docks and freight elevators enhance construction and provide storage space renters with efficient means to move in large items for storage. Among the issues associated with creating self-storage units are the wide variety of unknown contents that may be stored. Also, the tops of the units are often covered with an open mesh or chain link-type covering, which allows penetration by sprinklers. However, if the fire protection system is overwhelmed or not functional, it will allow fire in one storage unit to spread unimpeded to the exposed mill structure above (photo 7).

(7) When part of a structure is converted to self-storage units, firefighters are confronted with maze-like layouts. Units may contain tons of unknown and potentially hazardous contents. The enormous overall structure itself is an attached exposure.



When confronted with mill conversions, the district fire companies must take a proactive stance to operate safely and effectively in these structures. Preplanning and reconnaissance are the first steps to win any battle. Company officers should meet with the fire prevention bureau and obtain any information available on renovations in progress. A briefing from the fire marshal who has been in direct contact with the property’s responsible parties is always helpful. The marshal can give you his impressions as to the level of cooperation you can expect when conducting on-site preplanning.

In preplanning the building, the first-due engine and truck companies should make an initial visit. Establishing contact with on-site responsible parties, such as construction supervisors involved in the makeover project or a building manager at an existing occupancy, will help pave the way for the rest of your preplanning. A low-key approach is usually the most effective. By explaining that you are from the nearest fire company that normally responds to the property and mentioning your general goals and objectives and the fact that this is not a “code inspection,” the responsible parties will almost always be receptive to your visit.

When performing this recon while a mill is undergoing renovation, you have the added benefit of looking “behind the scenes” at the construction methods used, the new voids created, the closure of old shafts, and corridor layouts. You are also able to talk to the tradespeople such as plumbers, electricians, and carpenters working on the project. I have always had positive experiences when asking any of the trades on these projects questions about construction methods. Consider photographing important features and potential trouble areas. Developing a photo file of large makeover projects will serve as a great training aid and help members working other shifts or in fire companies across the city benefit from your efforts.


The gargantuan structures that housed the industrial muscle of a bygone era have been reinvented for a new century of service. Firefighters responsible for protecting these buildings in whatever state they exist must be resourceful and vigilant in preparing for and responding to emergencies in these structures.

DAVID DeSTEFANO, an 18-year veteran of the North Providence (RI) Fire Department, is a lieutenant in Ladder 1. He previously served as a lieutenant in Engine 3 and a firefighter in Ladder 1 for 13 years. He is an instructor for the Rhode Island Fire Academy, where he teaches various topics, including FAST operations and a ladder company program he codeveloped.

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