Concealed Spaces—Hidden Troubles for the Fire Department.
Concealed spaces within a building are always troublesome to the fire department in fire fighting operations.
The less experience members of the department have in building construction, the more dangerous concealed spaces become.
Fire may apparently be out to the untrained eye but upon investigation it may be found to have traveled or to be traveling to other points within a building, only to reappear or break out at some distant point leaving a trail of fire behind it.
Most firemen are familiar with the concealed spaces within plaster partitions and behind plaster walls.
In balloon frame type of construction where there are openings or passageways the entire height of a frame building these spaces constitute a particularly severe hazard because if fire starts in a lower part of the building it travels very quickly to the entire height of the building and involves the attic or cockloft with surprising speed.
Fig. 1 on page 25 shows a lath and plaster partition after a fire and also shows the ceiling spaces between the ceiling and the floor above where the fire has burned off the larger part of the lath and plaster.
Note in this particular illustration that fire starting in the basement of the building might have traveled up behind the book cases and not shown any evidence of itself until it had reached a point near the ceiling.
In operating at a fire men should employ all of their senses in detecting concealed fire. First, visual inspection will show discoloration of paint or paper which is certain to indicate hre burning behind lath and plaster.
If there is any question as to whether or not the fire exists in concealed spaces, feeling over the wall with the hand will locate the hot spots and will give the men a pretty fair idea of where to open up.
Then, too, the sense of smell is particularly effective in detecting burning articles or burning materials within walls or concealed spaces. Many a fire has been located through the detection of smoke, and the characteristic odor of the burning materials.
Hearing, too, is essential particularly in dark places in locating fire. The crackling of fire is distinctive and there can be no question of its presence when these characteristic sounds are heard.
Contrary to general impression wainscoting provides larger concealed spaces than lath and plaster walls or partitions. There is no appreciable thickness to wainscoting and as it is applied on the surface of the plaster it gives a greater depth of opening behind. Fig. 2 herewith shows the large space behind wainscoting where the wainscoting has been removed. (A) Shows the wainscoting removed and the open space behind it. (B) shows plaster removed with concealed space between uprights and faced on front and rear with lath and plaster covering.
Beware of wood finish on any surface where the room has been plastered. Note big. 3. Here the space around the door has been finished with matched lumber. Behind this lumber is an open space which would carry fire to the upper floor. Due to the thickness of the wood the presence of fire behind it in the concealed spaces would not be disclosed as readily as in the case of lath and plaster partitions which are either painted or covered with paper.
Fig. 4 brings out another point very vividly. Fire can pass within concealed spaces to adjacent building. This is what happened in the picture as shown in Fig. 4. Fire started at the rear of the two-story establishment and burned through the cock loft to the front. At the same time it passed through the wall, went up through the spaces between the outside sheathing and the lath and plaster of the three-story building, finally trapping a family in the top floor of this latter building. At this particular fire the father and three sons lost their lives.
After any fire do not leave it until it is absolutely certain that the fire is completely out. Take no chances on fires in concealed spaces but open up wherever there is a chance of fire burning. As previously noted use the various senses which you possess to detect concealed fire and before leaving the premises convince yourself that there is no possibility of any fire remaining concealed.