Fighting Fires in Taxpayer Buildings Raises Cockloft, Back Draft Problems

Fighting Fires in Taxpayer Buildings Raises Cockloft, Back Draft Problems

There is a type of store building found in most cities and towns across the country which can present several serious fire fighting problems. In many places it is called a “taxpayer” for a reason which gives a slight clue to the basic cause of the problems.

The name derives from a custom in the real estate investment business. An investor buys a piece of vacant commercial land which he expects will increase considerably in value over a period of years. In order to get enough income to pay the taxes on the property during the interim—and perhaps gain some profit from rents—he puts up a row of stores. This building is not meant to last a long time, and the owner wants it built as cheaply as possible. As a result, it usually ends up with structural and design features which the fire department should understand and be able to cope with during a fire. Some taxpayer fires can be quite dangerous to personnel as well as difficult to extinguish.

The foremost of these features is the common cockloft—the space between the top of the store ceilings and the underside of the roof. In some of these buildings it extends, undivided, over the entire row of stores. In others, there may be an occasional dividing wall, but because of weak construction or the presence of poke-through holes for pipes or cables, it cannot be depended upon to confine a fire.

Inasmuch as the partitions between stores may be flimsy and not firestopped, a fire may travel up into the cockloft where it will find plentiful fuel sources, and little or nothing to confine it. Because the cockloft space is large in area and often as high as 5 feet in the front of the building, it will have plenty of air at the start. In addition to the fuel supplied by wooden ceiling joists and hangers, roof joists, beams and boards, there will probably be a coating of combustible dust which will accelerate burning for a while. Of course, because electrical wiring travels through the cockloft, many fires originate in wiring and get a strong start before discovery.

Extension in cellars

While common cellars are not as frequently found as undivided cocklofts, they are not rare. Sometimes the division under the stores is no more than a wire fence from floor to ceiling. The fence may impede people (including fire fighters), but it won’t stop the passage of the fire. In some taxpayer basements the partitions are made of wood, often with large spaces between the boards. They won’t stop much smoke or heat, and will provide a lot of fuel arranged to ignite easily and burn rapidly. It is important to regard the whole row of stores as one large building in which the stores are merely rooms.

The cellar entrances vary from city to city, but are usually of three types: outside stairs (front, rear or both), inside stairs with full door at the top, and inside stairs with a trap door at the top. The inside stair with full door usually is next to the side partition of the store. It starts round the middle of the store and descends toward the rear of the basement. The trap door type is usually located near the back wall and descends at a steep angle. The top of each will be hard to find in dense smoke, and difficult to descend in face of much heat. The outside stairs are a blessing by comparison, but are still not an easy route if there is much fire in the cellar.

Taxpayer type of construction is exemplified by this block of stores.

One of the few advantages for the fire fighters is that the buildings are not tall. Usually they are only one story in height, although some are two stories.

In most locations the exterior walls are of masonry construction, but occasionally wood frame is encountered. Roofs are flat, usually the “built-up” or tar and gravel type on wood. They will burn readily and weaken quickly. Frequently there is a large skylight over each store in the one-story structures.

The occupancy of each store varies considerably. There are shoe stores, pharmacies, gift shops, beauty salons, etc. These stores and their basements can contain a large variety of combustible contents.

The life safety record of one-story taxpayers is excellent for the occupants but not for fire fighters, many of whom have died in such premises. The occupants of the one-story buildings usually escape readily from daytme fires and are not present at late-night fires.

Hazards to fire fighters

Fire fighters have been killed by a variety of causes. Some died from floor collapse due to heavy contents such as a baker’s oven or commercial refrigeration equipment. Men on the store floor and men in the basement have been killed by this cause, sometimes simultaneously. Roof collapse has also taken a toll of men on the roof when it gave way. Falling walls do not occur often with this type building and are seldom a cause of death.

Back draft has caused fire fighter fatalities in one-story taxpayers in more ways than one. The large-volume cockloft provides a place for the products of combustion to build up to an explosive mixture, which if ignited will react with sufficient force to blow the ceiling down, or to push out a portion of the wall. Both of these have killed fire fighters.

Cockloft area, space between roof and hanging ceiling, is visible in this unusual view.

There is the hazard of smoke, which can be guarded against by breathing apparatus, but in one case, fire fighters died of carbon monoxide accumulated in the basement which they returned to without breathing apparatus after the fire had been extinguished. There have also been cases of fire fighters trapped by a fast-spreading cellar fire, and even cases of drowning in the water from fire fighting in the cellar.

An action plan for a fire in a one-story taxpayer would call for the following steps:

  1. Find the fire. Just where within the structure is the fire burning? What way is it likely to spread? Can it be controlled easily or is there a good chance of it extending?
  2. These questions can be answered by the presence of visible flame or glow, or without that, by examining window glass by sight and touch for signs of heat. The concentration of smoke in a particular portion of the building could be an indicator, although it should be remembered that smoke may travel to one end of the building and bank up there, where its presence could be misleading.

    In some cases fire in a partition or up in the cockloft can be detected by the sound of crackling.

    Since further actions will be dependent upon the location and extension probability of the fire, it is important that these factors should be determined as soon as possible.

    During this time hose lines can be made ready but not definitely committed until the fire has been found.

    A crucial determination is whether or not the fire has entered the cockloft.

  3. Ventilate. The roof is the key location for ventilation, not only to retard the fire spreading through the cockloft, but also to prevent back draft. If the fire is in the cockloft it will be drawn to a hole in the roof. Therefore it is essential that such a hole be cut as nearly over the seat of the fire as feasible. One large hole is better than several small ones. There is a quick way to ventilate a store and its cockloft. It is done by removing the skylight completely, and with a pike pole, open up the sides of the skylight hatch which wall it off from the cockloft. This not only provides a vent from the store, but also the cockloft.
  4. The ground floor stores can be ventilated front and rear by opening the rear windows and breaking, if necessary, the show windows in the front. Sometimes just the removal of the transom glass is sufficient, but when conditions are severe enough to require breaking the big show windows, this step should be followed by removing any partitions at the back of the show window bench area.

    Cellar ventilation can be quite difficult. Smoke ejectors may be helpful if they can be put in place. Taxpayer cellars are entirely below ground level, but some have window wells covered by gratings which have to be removed or spread wide enough for a tool to be inserted and break the window.

    As ever, it should be remembered that not only will this ventilation accelerate the fire, but also draw it to the openings. This leads to the next consideration: having hose lines ready and in the right places when ventilation begins.

  5. Placement of hose lines. If fire is found in the basement, steps must be taken to keep it from traveling upward or horizontally. If it is not too severe, the fire can best be confined by extinguishing it quickly with the first line taken directly into the basement and additional lines stretched to the points vulnerable to fire travel. Most of the time this is effective; however, if the sizeup indicates considerable fire progress, it may be well to position the first line to prevent upward fire extension and use the second line to attack the main fire. This tactic is especially useful when there are both interior and exterior basement stairs.
Modern taxpayers frequently have steel roof decks supported by unprotected steel bar joists, which can be expected to fail early in heavy fire conditions.

If the amount of heat and smoke is great at one cellar entrance, it may be far less at the other. Once I saw a company stymied on the front stairs when they could have made it easily down the back. The front stairway acted as an exhaust passage while the rear served as a path to the fresh air being drawn to the fire.

Many of these stores have no floor extending under the window bench. If the panel under the show window is removed, it can provide an opening directly into the cellar which can be used for ventilation or even the application of water.

The use of cellar nozzles through holes cut in the floor of the store is a last resort tactic as would be the use of high expansion foam, which may very well subdue the fire in the cellar but will not likely overtake fire that is spreading upward between the walls. Distributors may be effective in stopping the horizontal spread in the basement (and the cockloft, too). They can be left in place, operating unattended for safety’s sake, if need be.

Every effort should be made to keep the fire out of the cockloft or, if it is already there, to arrest its spread. There have been many cases where fire fighters have pursued the fire from store to store, finally catching up to it at the end of the building. It may be necessary to go two or more stores ahead of the fire to make a stand that will stop it when it reaches that point. Although it takes moral courage to go into a perfectly whole store, as yet untouched by fire, and start pulling ceilings down, with adequate hose lines ready for when the fire reaches that position, this may be the only effective tactic.

Precautions

The following precautions must be taken in fighting taxpayer fires:

  1. Where the occupancy indicates heavy floor loads, floors may collapse during basement fires.
  2. Restaurants that use large amounts of gas for cooking might have a large gas leak due to melting at the big meter which would be present. Gas should be shut off in the street as soon as possible. Gas burning at the meter is not nearly as hazardous as the leaking of unburned gas. High expansion foam may extinguish burning gas, but it will not stop the leak which could cause an explosion later.
  3. Before a hole is made in the ceiling—from below—it is well to open the cockloft from above to lessen the danger of back draft when there is an accumulation of smoke in the cockloft.
  4. When a hole is cut in the roof it should not be made where it would endanger a taller adjacent building if fire broke through there later.

The term “taxpayer” may be regional, but this type of building is found throughout the nation. It is a building that deserves to be studied well in prefire surveys, and planned for accordingly.

THE AUTHOR:

Cockloft is used for running electrical and telephone conduits, shown here, as well as for plumbing pipes and ductwork for heating and air-conditioningSteel roof decks of some taxpayers are supported by steel beams and girders.

Author

No posts to display