Challenges of Older Structures


For as much time as we in the fire service dedicate to reviewing and preparing for the challenges of lightweight construction, it is also important to review some of the challenges found in older structures, especially if your jurisdiction has a large number of them.

Many years ago, as a young firefighter assigned to Ladder Company 12 in the Jersey City (NJ) Fire Department, I remember an older seasoned firefighter who took me under his wing, telling me that after a room or floor is burned out in an older frame or brick building it was important to pull and remove all the door and window trim in the apartment. “Great advice that we continue to pass on to our new firefighters today.”

He would go on to say that the space between the rough opening and the window and door can vary from as much as ¼ of an inch to a few inches, depending on a number of factors that affected the installation at that time. This area, where the wall’s plaster and lath ends and the door or the window begins, is only protected by the wood trim covering. If the wood trim is compromised in any way or has significant charring, fire can burrow in and behind the furred-out spaces around the door and window openings. If fire or a significant amount of heat is allowed into this space, most notably to the back side of the plaster-and-lath covering, it will allow fire to spread behind the window and door enclosures and into the building’s void spaces. At the very least, he said, you have to anticipate that any compromise of these areas can allow a fire to smolder for hours and eventually spread. Therefore, he insisted, “Open it up!”

In advising me of the above concern, he also spoke of three other overlooked areas within old frame and brick structures—window ballast pockets, the possible presence of sliding pocket doors, and transoms.

Window ballast pockets. Window ballast pockets are found in old double-hung wooden sash window enclosures. If an older sash window is still in use, one clue that there’s a window ballast pocket is the presence of a rope or chain inside the track of the window sash. Lengths of rope or chain attached to the window sash were fastened to tubular cast-iron weights hidden within pockets at the sides of the window frame. These weights are designed to slide up and down within the pockets to counter the weight of the window sash, allowing the window to stay open. On average, the cast-iron weight is about two inches in diameter and 10 inches long and can weigh as much as five pounds. Its design allows it to ride up and down in the vertical channel or pocket for the entire height of the window.

In many older building renovations, the older wooden window sashes are replaced with newer and smaller replacement windows. They are often installed within the existing opening that held the original window sash, leaving the original voids or pockets still in place. For ease and speed of installation, window installers will just cut the rope or chain attached to the older sashes and let the ballast weight fall and remain in its original pocket. This allowed installers to simply remove the older wooden window sashes to make room for the new and smaller window to be installed within the existing opening. But as new and solid as the new replacement window will appear, if fire compromises the wood trim around it, the original void space will allow fire to travel in and behind the structure walls (photos 1, 2).

Photos by author.
1 Photos by author
Photos by author.

Sliding pocket doors. Sliding pocket doors were incorporated into an apartment or home to give privacy between rooms. The doors are often large and designed to be pulled from within the wall opening. The interior wall that houses the pocket or opening has a wider frame than the other walls within the building to allow the entire sliding door to disappear within.

For firefighters, two immediate concerns must come to mind. First, if the doors are still in use today, the fire has early and easy access into the sliding door’s opening and the pocket. Second, the width of the pocket door wall is a concern. This is a much wider wall that is not only designed to house a sliding pocket door but also represents a large void space within the building’s structure. This opening could easily allow fire to gain access to the building’s void spaces.

Because of their aesthetic value, many pocket doors are still in use today. For those no longer in use, you have to expect that some may have had their openings trimmed over. This may delay fire from extending in and behind the walls; but again, if fire compromises the wooden trim, fire can extend to the building’s void spaces (photo 3).


Transoms. Transoms are small windows designed and incorporated above a door. Their original intent was to allow light and possibly air into a room. They can often be found in older frame dwellings, schools, row frames, multiple dwellings, and brownstones. You can also find them in newer and modern homes and offices because of their aesthetic value and appearance (photo 4).


In many older installations, homeowners have restored their use and appearance to add to the home’s decor. But as decorative as some may appear, they present a significant concern to firefighting forces. With older transom designs, all that prevents fire from penetrating the opening is a single pane of glass. Also in older designs, transom openings were mounted on hinges to allow airflow. Opening and closing of the transom was/is done by pulling on a cord or decorative chain. If the transom was left open, or if the hinge mechanism failed or was damaged, smoke and eventually fire would penetrate the opening sooner.

What was of great concern to firefighters years ago and still is to some degree today is the transom opening installed over an apartment door in a multiple dwelling. As fire spreads throughout the apartment in a multiple dwelling, the transom’s single pane of glass would quickly fail, allowing fire and smoke into the public hallway. Over the years, city fire codes required the openings to be covered by plywood or gypsum. But as years pass, those coverings may become compromised, presenting the same dangers of years ago. My mentor from Ladder Co. 12 advised me to take a quick look at the condition of the transom openings on the fire floor, especially when we were assigned to search the floor above the fire. He declared, “If they fail before the engine company has water on the fire, the staircase will become compromised, requiring us to have additional means of egress sought out, so let’s be prepared.” This is sound advice that I still pass on today.

As much as we discuss and stress in our teaching the concerns about how a structure is built, we must also remind our members that building features not only influence our decision making but also affect our safety. As we continue to share information and educate today’s fire service, it is important that the information sharing include the old as well as the new.

MIKE TERPAK, a 36-year veteran of the fire service, is a deputy chief and citywide tour commander in the Jersey City (NJ) Fire Department. Throughout his career, he has worked in the city’s Lafayette and Greenville areas with Engines 10 and 17, Ladder 12, and Rescue 1; as chief of the city’s 2nd Battalion; and as former chief in charge of the city’s Training Division. He lectures nationally on fire/rescue topics and is the founder of Promotional Prep, a New Jersey-based consulting firm that prepares firefighters and fire officers studying for promotional exams. He has a bachelor’s degree in fire safety administration from the City University of New Jersey and is the author of Fireground Size-Up, Assessment Center Strategy and Tactics, and Fireground Operational Guides (with Frank Viscuso) (Fire Engineering).

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