Proper Venting of Buildings Involved with Fire
Report of the
Committee on Fire Manual
International Association of Fire Engineers
IN fire extinguishing operations it can be correctly stated that the venting of a structure, involved with fire, is one of the important and very necessary duties carried on by the force engaged in its extinguishment.
Some of the higher ranking officers in many fire departments are opposed to the theory, and in actual practice will not permit their subordinates to operate on the structure in such manner as will either partially or wholly relieve it of the accumulated smoke and heat which is produced by the burning of the contents or structural parts of the building.
Those very things that prevent and delay the quick extinguishment of a fire, whose presence in a structure have produced conflagrations, to say nothing of the fabulous sum in money value lost on contents and structures at fires of a lesser degree.
Are there not thousands and thousands of fires occurring every year throughout the world, incipient, of course, at the moment of their origin, even incipient when the alarm is sent in, and still incipient when the fire extinguishing force arrives, and would be extinguished very quickly and with little damage to contents and structure, but for the fact that something had accumulated that frequently delays, and on occasions prevents the force from reaching the seat of .the fire.
What had accumulated?
Nothing but heat and smoke, the powerful barrier which is the most prolific cause for the birth of the Nation’s Ash Heap, which authorities state represents a value of approximately $250,000,000.
The heat and smoke barrier is not always insurmountable, because of the strong physique, grit and stamina of the firemen engaged at an operation, who willingly and cheerfully assume the risk of death by suffocation, severe physical suffering or permanent disability in their efforts to overcome it.
The records of many fire departments will prove the accuracy of this statement, and will show that, at injuries, of a greater or less degree, in their efforts to overcome the smoke and heat barrier and cause the fire’s extinguishment.
This statement is not an exaggerated one, and for confirmation as to its accuracy, let each fire officer give thought to the fires that he has operated at during hi time of service in the profession and calculate upon the frequency with which he came in contact with heat and smoke at fires of trivial proportions, where, if it were not for the presence of the heat and smoke, would in the language of a fireman be quickly extinguished with “a dash of water.”
Smoke or heat prohibited the advancement of the first hose line, so that its output of water could not be distributed over the fire area, and other lines had to be stretched and additional water thrown into the structu re.
An officer reaches the seat of the fire, after a prolonged battle, the smoke having cleared up, and looking about him he views the small area that the actual fire had come in contact with, and he can at the same time view the large area covered with valuable stock that has been damaged bv water and which has not been touched by the fire.
Does not a result of this kind justify the theory that a building involved with fire should be vented at this or that point, where it will quicklv cause the liberation of the heat and smoke confined in the structure, which will be of material value to the firemen working to extinguish it ?
The prompt liberation of the heat and smoke creates a condition in thousands of operations that permits a more speedy advance of the line or lines to the seat of the fire, and its extinguishment is more prompt, which is the object you arc trying to accomplish.
Let it be clearly understood that it is not claimed that the venting of a structure is solely responsible for the extinguishment of a fire, or that it would have any great value in cases where, upon the arrival of the first officer, it was found that the fire had extended “Report prepared by Deputy Chief T. F. Douirherty. fficer in charge of the New Ycrk Fire College, and apnroved by Chief John Kenlon, President International Association of Fire Engineers 1919 1920. throughout a structure or nearly so, but these instances are only a small j>crcentage of the total number and are only referred to for the purpose of bringing about a clear understanding of the theory.
a considerable number of fires of insignificant proportions, firemen have lost their lives, and others in large numbers have received permanent or temporary
An officer on his arrival should be on the alert and give thought to the venting of the structure, without a moment’s delay, consider the fire’s location or the line of its possible extension, and open up such portions of the structure as common sense and experience dictate.
When we say “open up” as the term is used in fire departments, it implies that window sashes are to be raised or lowered when possible or broken when conditions call for it; the opening of transoms over doors; the breaking when necessary of such plate glass in store fronts (show windows) and the glazed sashes located a few feet back usually used in conjunction with it; the removal of wood or glass covering over elevator shafts, stairways, light, air, vent or dumbwaiter shafts, including skylights and scuttles or a portion of the roof.
An officer in charge of a fire should have considerable pride in an operation that has been carried on under his direction, where no unnecessary damage to property has resulted from the work of the force engaged.
And there are occasions when an officer will hesitate as to opening up this or that portion of a structure; he has to order that plate glass or some other part of the structure be broken or damaged; he will not assume the responsibility as his own, or it may be that there are standing orders from a superior that prevent his doing this or that thing that is vitally necessary in preventing the fire’s extension or of assistance in its quick extinguishment.
Let there be no hesitancy whatever as to the venting of the structure; the small money value of the damage you may cause is nothing as compared to the value of the structure and its contents, and thousands of cases could be cited where conditions threatened the loss of the structure, but prompt venting of same resulted in a comparatively insignificant loss to the structure and its contents.
All fire officers recognize the frightful rapidity with which fire travels through a stairwell or vertical artery, and the immense volume of smoke generated by the combustion, which in a very short period of time would be of sufficient volume to fill every portion of an unusually large sized structure.
The heat and smoke travel through the stairwell, elevator vent, light, air or dumbwaiter shaft, only vertically, neither going to the right or left, forward or backward, on any of the intermediate floors, until it can travel no further, because it has met with construction that has interrupted its progress and acts as a deflector.
This deflection of its travel creates what fire officers call the “mushroom” condition, and instead of its movement being upward, it is forcing itself to the right, left, forward, backward and downward, and will in a very short period of time involve all of the structure with fire.
Let us suppose that the escape of men, women or children have been cut off in a structure under the conditions described above. Is not a loss of life almost a certainty? Therefore the prompt venting of structure at the point that will draw the heat and smoke up and out will at times result in the saving of life as well as a property saver.
At this point no great harm can be done in offering a suggestion to owners, builders, architects and insurance interests to give serious consideration to the value of an automatic vent for fire on the roofs of structures, immediately over all vertical arteries that extend through the building, such vent to be equal in area as the area of the shaft.
We make the claim that it would be a wonderful assistance in the saving of life and bring about a large ly decreased loss on buildings and contents.
This country is rampant with its cry of “Fire prevention,” both in educational and structural measures, all with a view to preventing fires.
Fires will occur until the end of time and will have to be combated with by human and mechanical forces, and considering the types of structures in existence to-day, and which will be in existence for many years to come, there is nothing of more value than an automatic outlet applied as hereinbefore stated.
The insurance interest maintains a wonderful laborator)’, and could with little expense or outlay make such experiments as would either prove or disprove the value of the theory of an automatic vent or the present methods now utilized in venting a structure involved with fire.
In actual practice it is customary to follow the methods that experience has proved have beneficial results, but rapidity of action is absolutely essential.
No “opening up” of any portion of a structure should be permitted that would increase the draft and hasten the combustion, until such time as a charged hose line is immediately available to combat the fire; but this should not be understood to fully apply to a fire that is travelling through a shaft or stairwell, as the coverings at the top could be promptly removed, which would be a benefit rather than a handicap.
Regarding the operation of opening up some portion of a roof for the purpose of obtaining a vent, which frequently is an absolute necessity, it is suggested that an officer should be extremely cautious in ordering that this be done, unless conditions call for it.
In many cases roofs are opened up unnecessarily and hours or days after the fire rain storms have developed that caused a greater damage to the contents, through openings in roofs, than was caused by the fire itself.
Fires in cellars or sub-cellars of factory buildings require that the top of elevator shafts should be opened for a vent, and a very liberal opening up of doors and windows of first floor, both front and rear, and this will probably permit (if it is done promptly) of companies holding their positions on this floor and be of material aid in confining fire to a cellar or subcellar.
Large plates of glass are valuable and smaller plates proportionately so, and it is found necessary at times to break them. Show window construction of the present day has two plates on front or sides, the larger one at the bottom of the window frame and smaller one at the top.
The top plate is the one that should be broken, if the transom or open doorway is not sufficient for venting purpose.
Usually in show windows there is an inside glazed sash, that even though outside plate was broken, would obstruct the outlet of heat and smoke, and where present it is absolutely necessary that it should receive consideration at the hands of a skillful truckman, for the purpose of creating an unobstructed outlet.
At fires on top floors of factory buildings, heavily charged with smoke and heat, it is recommended that if it is found necessary to obtain a vent, by opening the roof, that such vent be made at a considerable distance from the line of the stairway, as the heat and smoke will be drawn through such opening and away from men trying to make the floors, and in addition, such outlet as may be made directly over the stairway should be opened up promptly.
Opening window shutters by way of fire escapes should be begun at the top, man to work with wind at his back, and open the most distant shutter first, all glazed sashes to receive proper treatment as conditions call for.
In many cellar fires, particularly tenement, flat, apartment houses or dwellings, stubborn fires are frequent, and nothing better can be done than to take up a floor board in hall or in one of the rooms of the apartment or store over cellar, and the value of this operation to men trying to make the cellar cannot be over-estimated; a charged line should cover any opening so made, and there will be no danger of fire extending through such opening.
This method would also apply to a factory building, but should only be carried out on orders of a chief officer or the head of the department, who would of course make proper estimate as to the extension of the fire through any opening so made.
Opening up windows above the first floor of buildings where no fire escape is available.
Where a large number of windows are to be opened it can be done quickly with a ladder, by shifting ladder from window to window, allowing top of ladder to fall against glass.
Beyond the limits of a thirty-five-foot ladder, an extension ladder can be utilized within the limits of its reach, and beyond the limits of the reach of an extension ladder it is recommended that a scaling ladder be manipulated from floor below to open up windows on next floor above, and in a good many cases a stream of water directed against glass has been the means of promptly providing a vent.
When coverings over elevator shafts and skylights are removed for the purpose of obtaining a vent, it is good fire practice for a man to lower a hook through such opening for the purpose of ascertaining whether the smoke and heat has an unobstructed outlet, as on many occasions it will be found that an additional glazed sash is located at ceiling level below and is an obstruction which should be opened up promptly.
When an opening is made in a roof, the lath and plaster ceiling directly thereunder should he pushed down with hooks, otherwise opening in roof will have no value.
Fire that has extended to a cornice is on many occasions troublesome, as it frequently travels from building to building because of the absence of a proper fire stop between buildings.
In operations on cornice fires men are prone to make an opening in the cornice at or near the roof level, and any opening so made has very little value, as the pentup condition of the fire still exists, and it is still extending in a right and left direction through the large void that a cornice usually provides.
It is recommended in cornice fires to first make a fairly good sized opening, or more than one if necessary. at or near its peak as quickly as possible, with a view to preventing the fire’s extension, and later such other openings as are required may be made.
On many occasions fire has extended through nonstopped stud partitions, from floor to floor, usually along the line of folding doors, and as a rule finds its way to great big void under roof or hanging ceiling, as firemen name it.
In a case of this kind, where an officer recognizes this condition quickly, good results are obtained by making an opening in roof directly over the line of the fire’s travel.
The use of the hand in locating a hot spot on a roof is good practice, as on many occasions it has clearly indicated where an opening should be made; similar information has been obtained by observing blistered condition of the paint on a tin roof.
In making openings in roofs involved with fire, consideration should be given to adjoining exposures, as side window openings therein might increase the hazard.
Where several buildings comprise a row, all of similar construction, and attached one to the other, where there is no interior connection between buildings below the top floor ceiling level, a large open void called a cock-loft is generally found between the top floor ceiling and the roof, which extends over the full area covered by all of the buildings.
In the event of fire occurring in any one of these structures, and appearances indicate that it will extend to the cock-loft, prompt measures should be taken to head off the fire by a liberal opening up of the roofs of buildings on each side of the fire building
Where the fire has already gained a foothold in the cock-loft and is spreading horizontally in both directions, such openings should be made a sufficient distance ahead of the fire, with a view to interrupting and diverting its further travel through the cockloft.
In venting this cock-loft construction, it is good practice to remove one or more roof boards in a straight line from front to rear end of the building.
It may be that a building is in an isolated position in a territory where congested construction does not exist, and, because of the absence of an adjoining structure, might deter an officer from attempting to obtain a vent or outlet on the roof, but it is absolutely essential that the vent be provided and there should be no laxity in the efforts made to obtain it.
At cellar and sub-cellar fires of prolonged duration, when officers and men were enabled to enter, they have frequently l>een overcome, although little or no smoke or fire was present at the moment.
This condition is due to the presence of a heavier than air gas or vaior, generally carbon monoxide, which has been produced by the combustion.
After a period of time, these gases or vapors dis sipate themselves, and officers, with a view to their liberation, have taken up floor boards as a vent, but their efforts are a waste of energy, as no benefit whatsoever is derived from the vent so created.
For the liberation of heat and smoke, open up at the top, but for the liberation of carbon monoxide or other heavier than air gases or vapors, make an opening to outer air at or near the floor level where they are confined, and where this is not possible wait until they are dissipated.