Basement Fires
Departments
Volunteers Corner
Basement fires have been a special problem to the fire service for a 19 long time. Fighting basement fires demands respect for the potential hazards involved, good application of ventilation principles, and an aggressive interior attack. Now, there are some additional considerations due to new building construction techniques.
New construction problems
Singleand multiple-family living unitsare now being built with wooden trusses, wooden I beams, and box beams to support the floor above the basement. These lightweight supports increase the possibility of collapse. In addition, firefighters will encounter problems with hidden spaces and horizontal chases that will enhance fire spread above the ceiling.
These two situations intensify each other. As the fire spreads above, within the ceiling space, the supports will become damaged and the connecting gusset plates will fail. This will lead to an early, unsuspected collapse. Fire.fighters below may be trapped; those above may plunge into the inferno.
Another difficulty with new construction is the use of unprotected vertical shafts. These can cause a fire to spread upward from the basement to higher floors or the attic, or drop down and ignite combustibles in the basement. These unprotected shafts may consist of unstopped plumbing or electrical chases with plastic pipe or combustible insulation, laundry chutes, pre-piped vacuuming systems, or space around heating ducts and other pipe assemblies.
These are all new construction problems that the unwary firefighter must be made aware of. You should prepare for possible incidents in these structures before they occur.
Structural problems
Every basement, even if it was not built with new construction techniques, has its share of structural problems. Hidden spaces and unprotected horizontal and vertical openings abound. In commercial areas, horizontal openings often extend from building to building. These openings can be for utilities or heating/air conditioning purposes. Fires in the basement may run across the ceiling rafters spreading fire from one end of the building to the other.
Another problem is the weakening of unprotected steel columns and beams that could lead to an unexpected floor collapse. Local collapse may also occur if shelves or ceiling attachments on the floor above give way. The fire officer must always be aware of all these safety problems in making a thorough size up.
Storage materials
A major hazard at every basement fire involves the materials that are stored in the area. Whether the fire is in the basement of a residential or commercial building, the contents are often dangerous when exposed to fire and related firefighting tactics. The quantities may be greater in a business, but there are many residential basements that have more than their share of potential hazards. Just review what is stored in your basement.
There are always the utilities. Electrical hazards and gas meters may be present. Many occupancies have a large fuel oil tank adjacent to the furnace.
Almost anything can be stored in the basement: shell reloading materials for the sportsman, paint and adhesives for the handyman, stains and varnishes for the woodworker, all sorts of pesticides for the gardener (or merely survival from the insects), cleaning compounds, fuel for camping equipment, swimming pool chemicals, and a flammable gas torch for repairs to name only a few.
Commercial establishments may have a far more extensive storage list. There are also the illegal drug manufacturing operations and terrorist caches that cannot be overlooked. Finally, do not forget about the exotic pets (or not so exotic guard dog) that range from large cats to boa constrictors.
Pre-fire plans
Because there are so many often unsuspected problems, you should make pre-fire plans of all commercial basements. Because apartment buildings generally have large storage areas, they also require pre-fire plans. During home inspections, make a special note of all basements that are particularly hazardous.
The basement pre-fire plan must include items of major concern: unusual construction features, access, ventilation operations, attack approaches, avenues of fire spread, need for confinement, rescue requirements for occupied basements, and, of course, any and all storage, utilities, and special hazards.
Ventilation
Ventilation can be a serious problem in basements that encompass a large area or are divided with many partitions. It may be necessary to use mechanical methods to create a positive or negative pressure forced venting. Placing fans at both ends of the basement may help push and pull the heat and smoke out.
Where windows and doors are accessible, fog streams can be effective. Horizontal ventilation is the most common method that is used with these fires. Window wells, delivery entrances, or sidewalk openings can be used.
Vertical ventilation is difficult because there are so few openings leading directly to the outside. In balloon construction or buildings with unstopped vertical openings, it will be necessary to immediately open the roof. This will avoid the buildup of convected heat that could possibly ignite a second fire at a remote location. Soffits under show windows will provide a vertical artery from the cellar to the street in some buildings. All possible ventilation avenues should be preplanned before the alarm.
Attack procedures
Attack procedures follow many of the basic tenets. There must be coordination between the ventilation and hose crews. You must use attack lines that are large enough to cover the potential fire involvement area of the building.
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Get in front of the fire and stop its advance. Don’t stand behind it, pushing it further into the basement or throughout the structure. Vertical avenues of fire spread and the floor above must be protected with hose lines in place. Check and protect the attic or cockloft space.
Be alert for the backdraft or flashover; it can occur in a basement, even if the first floor is ventilated. Watch for burnt-through or sagging floors or stairs, which could cause serious firefighter injuries or possible death.
Remember that the attack team at the top of the stairs is looking into a chimney. Once the decision is made to advance, the crew must go all the way, getting below the heat buildup at the basement ceiling level.
The rookie may want to stop because it is getting hot in the basement. He may not realize that the heat buildup is only at the top one-third of the basement height and that it will be much cooler at the bottom of the stairs. Adequate venting will help alleviate this problem.
Finally, you should perform extensive overhaul. This is to ensure that the fire is out and that it has not extended through some hidden opening to other parts of the building.
Summary
Basement fires are dangerous. Officers must always exercise discipline over the firefighters to ensure that all operations are carried out safely.
- When fighting a basement fire:
- Remember the hazards,
- Consider all options based on a detailed size up,
- Initiate ventilation,
- Apply sound and safe attack procedures.
Following these guidelines will help control the fire with a minimum of property damage and injuries.
