Basements and cellars are the most dangerous fire locations inside of a structure. With limited access, egress, and ventilation options, be prepared to take a hit at the top of the stairs.
Fires in subdivisions have killed more firemen than all upper floor fires have. Descending down a chimney of intense heat and hot gases from above to fight a below grade fire is no easy task. There are several dangers the company officer will have to address before advancing on a fire in a subdivision or checking the fire to protect egress of occupants.
Concerns for first due engine crews are intense heat, limited visibility, floor collapse, stair burn through, entanglement, limited ventilation, secondary means of egress and the occurrence of a hostile fire event, especially in areas with taxpayers, lightweight construction, and long reflex/response times.
Basement vs Cellar: If half or more of the height is above ground (or the curb), it's a basement, if less than half is above ground, it's a cellar. Some garden apartments and brownstones will have their first floor slightly below grade. If it's a living space, and more than half the height of the apartment is above the curb line, count it as a story.
Size Up: When arriving to a basement fire it's important to identify key size up indicators that will be of concern in the first several minutes of operation. In addition to any life hazards, identifying lightweight truss, balloon frame construction, structures built on a slope or hillside, combustible exterior siding, bars on windows, and renovated buildings are just several concerns that will influence your initial strategy and tactics. Response time, trapped occupants and manpower will also factor into your tactical decisions. Recognizing the reported fire location given by dispatch, weather conditions and time of day before you even leave the station puts you ahead of the game. Confirming location and extent upon arrival will help determine any rescue options, access, ventilation options, and line selection.
On approach, look for exterior cutout or Bilco doors as an option for secondary egress, fire attack, or ventilation. Take a quick look inside the basement window while stretching the line. For trapped occupants on upper floors, have a charged line for protection of the normal escape route (interior stairs, front door) and consider starting ground ladder placement for VES.
Exterior Fire Spread: Vented basement fires will have to be stopped from spreading up the exterior siding. Fires that are not venting from well windows can still spread up the interior wall through void spaces, especially in balloon construction. Stop any vertical exterior fire spread by quickly applying water from exterior and opening up the siding.
Construction: Not all basements are the same. Basements in urban areas with ordinary construction will differ from those in rural and suburban areas with wood frame construction. An urban basement may have low ceilings, hoarding conditions, illegal boarding with partitions, oil burner, exposed utilities, open stairs, and unprotected 2x10 dimensional lumber. The suburban basement may have a large open space with 10' ceilings with an engineered lightweight I-beam floor above, protected by drywall. It may be used as an entertainment room, or an apartment with a rear cutout or bilco entrance door. A row of taxpayers may have common basements with trap door access in the rear of the first floor commercial business with exterior access through sidewalk cellar doors.
During size up, try to determine the construction and occupancy type. Although not an exact science, this information may help determine the floor support system, access/egress points, and contents burning below. If a 360° isn't possible, do a 270° and assign another company (or BC) to check the rear, especially if you have a row of attached homes. If it's a wood-frame balloon constructed home with fire, we already know to quickly get crews to the upper floors and loft to stop the vertical fire spread. If floor supports are engineered I-beams, fire will quickly burn through the web member and weaken the connection points. Steel C-joist concerns are deformation and connection failure.
Location and Extent: Determining if it's in the basement can be difficult if you arrive to smoke showing on all floors with no visible fire. Check the basement windows, gather information from the residents, use a TIC on the first floor (perimeter/registers) or perform a 360° size up. Upon entering the front door to make your way to the interior basement stairs, high intense heat is an obvious sign you have fire below. If you have heavy fire venting out of the basement windows on arrival, consider a coordinated transitional attack.
Water Extinguisher: You would be amazed at the amount of BTU's a few water cans will absorb in a basement fire.
Line Selection and Placement: For basement fires, the first attack line should be a smooth bore nozzle. With a limited ventilation fire in a container below, less steam production and more GPM's, it's the obvious choice. The attack and backup line should be charged BEFORE entering the basement. The fog nozzle (or breakaway) as the second line is not always a bad choice, as it helps with hydraulic ventilation to clear smoke/steam out of the basement and improve visibility after a quick knockdown. The second line must stay charged on the first floor ready to go in case the attack line has a problem. Firemen have been trapped, injured and killed in basement fires by hoselines being burned through on the floor above.
Determine the best entry point to attack the fire. If there's an outside entrance, stretch through there IF it's a better option. Most of the time in urban residential structures, especially row homes, it's the front door to the interior basement stairs. Make sure to check which direction the interior basement door opens before you charge your line. If it opens towards you, it may be difficult getting past the door with the line (once charged) and in position to descend the stairs. In that situation, it may be better to flake excess line past the door into the next room, and advance from that direction. If the interior basement door opens away from you, the products will hit you quickly, but at least the line won't be pinched under the door. Door control must be maintained until the line is ready. If the door has burned through, preventing the vertical fire spread becomes priority.
TIP: Do not open a line in the window or bilco door while interior crews are advancing down the stairs or inside the basement
For commercial buildings and taxpayers, it's usually the interior basement stairs, although exterior entrances and sidewalk doors have been used before for fire attack. These openings better serve as ventilation points. Be aware of hinged trap doors inside that may be left open. Firemen advancing in low visibility may fall through them into the burning cellar. These are common on the first floor in ordinary constructed mercantile-taxpayers.
In large area basements and cellars, do not lose contact with the hoseline! During an emergency, it can lead you back to the basement or cellar steps.
REMEMBER: Life safety is the top priority. The initial attack line will first protect the interior stairs for escaping occupants, fire spread, and firemen conducting searches above.
Collapse: The first due company officer and nozzleman will have to check floor stability when crossing over to make the interior basement door with fire below. The construction of the building may give firemen a good idea of the type of floor, but they will be unaware of any renovations that were done. This check for floor stability is usually an educated guess by the company officer unless the obvious signs are there (prior fires, sagging floor, spongy deck, plywood burn through). If the attack team is met with unbearable heat, and carpet melting to their turnout gear, these are warning signs of impending flashover and a weakening floor..
A floor support system in an unprotected I-beam lightweight or hybrid truss system can fail in as little as 5-7 minutes when exposed to fire. There's really no way to be 100% sure if it's safe to operate on the floor above the fire. TICs and sounding the floor are not always reliable, but if the floor feels spongy or there's fire coming out of the baseboards, floor vents, registers/returns or sagging carpet, these are not good signs!
During UL tests on basement fires there were no signs prior to collapse. Increased ventilation, fuel load, span, and added load from the weight of firemen in full gear increase chances of collapse. Residential basements underneath kitchens have heavy appliances above them. Commercial properties may have storage, machinery, supplies above, adding weight to an already weakened floor. (See Buffalo LODD)
Other concerns for collapse are long response times and the contents burning in the basement. Responding to a fully furnished family room basement fire in a rural area that has been burning for 20 minutes before the first company arrives means there's a good chance of floor collapse. Even in the city where several companies arrive on scene within several minutes, firemen may be walking into a basement fire with hoarding conditions, unprotected floor joists, and low ceilings with fire fueled by mattresses, gas cans, hoarding conditions, and other junk stored in urban basements. Factor in delayed discovery, and the chances of collapse increase.
When the decision for an offensive attack has been made, the line charged and ready to advance, sound the steps on the way down. Open stairs with fire below exposing them will weaken stairs causing a collapse when weight is applied (if not already burned through) especially 'cardboard constructed' engineered lightweight I-stairs with 2x4 supports, OSB and gusset plates (pictured above). Sound the center of the step for stability, descend on the outer stair near the supports.
Stair Collapse: A major concern for the nozzleman making his way down to the basement. Engineered lightweight "I" stairs will collapse fast when exposed to fire. When lightweight construction is present on arrival, expect these cheap stairs. Check stability of steps and descend at the stringer.
Burn Time: Underwriters Laboratories performed testing on floor collapse during basement fires with different types of flooring systems. Collapse times ranged from 3:38 to 12:45, with (unprotected) dimensional lumber averaging 11:57 and engineered flooring systems averaging around 7:00. With all of these tests, there were no reliable signs of floor collapse. Sounding the floor with a tool or using a TIC is not reliable when checking for floor stability.
When it comes to floor stability, it isn't just about the type of flooring/lumber in a newer home, but how it's supported, whether the supports are protected or unprotected and how long it's been exposed to fire.
What type of floor supports and how long have they been burning? Add the weight of firemen crawling over this already weakened floor on the way to the basement door.
DO NOT CREATE FLOW PATHS TOWARDS THE ATTACK TEAM AT THE TOP OF THE STAIRS
Although rare, with the right conditions present, breaking basement windows or opening BILCO doors on the windward side while firemen are advancing down interior stairs will create a dangerous flow path.
Many taxpayers have metal cellar door access on the sidewalk in front of the building, but they may be heavily secured from the inside to prevent theft. Do not use the interior basement stairway for a vent point as the fire will be pushed into the rest of the building. Cutting holes in the floor is time consuming for ventilation and may jeopardize cutting structural supports (better for flooding cellars). Using positive pressure ventilation (PPV) will be effective in certain conditions, but it's usually more effective after extinguishment.
Flow Path: With an open basement window (or bilco doors) some wind, an open interior basement door and the right fire conditions, a dangerous flow path will be awaiting attack crews at the top of the stairs.
While dangerous flow paths will not be an issue at every fire, it is still necessary to recognize the conditions and understand how they are created.
ATF Mayday/LODD fire modeling analysis with scene audio, FF Mark Falkenhan, Baltimore County FD
Rapid Intervention Team: RIT priorities at a basement fire will be providing the hose team with an additional means of egress BEFORE they need one. Immediately removing bars from basement windows, AC units in windows and performing a 360° to see if any other escape routes are available should be done right away in case a problem occurs. The attack crew entering through the front door in what appeared to be a 2 story home, may be a 3 story from the rear with a walk in basement entrance. This discovery has to be reported to the IC immediately.
Be prepared to rescue firemen trapped in the basement during a floor or stair collapse. Methods of rescue will depend on their location, entanglement, fire conditions, air supply etc.. A proactive RIT team will have a ladder, webbing/rope, cutters, maul, and RIT pack ready to go.
During fire attack in the basement, if the hose teams access back to the basement stairs is cutoff by fire, or they can't locate them in poor visibility, use the radio and direct them towards a basement window, bilco door, or other egress point. (Why lights on helmets/coat help)
Incident: In 2006 during a basement fire in Trenton N.J, three firemen became trapped on the interior and issued a mayday. The two firemen operating the hoseline in the basement had their egress cutoff during a first floor flashover. In addition, their hoseline had burned through.They were directed to a window by a proactive officer and other members on scene who pulled them out just in time. The third firefighter feeding them line on the first floor survived after being caught in a flashover just several feet from the front door. He was rescued by members on the porch who entered the fully-invloved first floor to pull him out.
Some firemen will have trouble escaping through cellar windows above them wearing the full PPE -SCBA. They will have to remove their SCBA with facepiece still attached, reduce their profile and be pulled out by members on the outside. Enlarge the exit window if possible.
It's IMPORTANT during a MAYDAY that members NOT involved with the rescue USE RADIO DISCIPLINE, unless it's a priority/mayday. Continue assigned suppression, search, ventilation duties, and remain on the proper channel. This is often a problem!
TIP: When arriving to a confirmed working fire in a sub-division, the IC should immediately assign the RIT team officer or another member to have a scissor/collapsible ladder or straight ladder ready to go by the entrance, in case of a floor collapse. A good proactive RIT team at a basement or cellar fire will have a sledge hammer and other tools ready to help increase the size of basement window openings, just in case.
Entanglement/Entrapment: Advancing hose teams should be careful when venturing deep into a basement fire (and attic) because the potential for entanglement and entrapment are high. Basements and cellars in urban areas will have hoarding conditions, illegal boarding-renovations, partitions, furniture, storage, washers/dryers, clothes lines with wire hangers, bicycles, crates, lawn equipment, drop ceilings, utility wires, entertainment centers, oil tanks and heaters. With little or no visibility, use extreme caution and move slow while advancing. Staying at the base of the stairs is usually a good place to attack and knock down the fire in a residential basement. When conducting the primary search, be cognizant of all the clutter inside of a basement that can trap and entangle you including crawl spaces, closets, appliances, sleeping areas and common basements. Always look for that window or other escape route while entering the structure, hitting the fire, venting or searching. With low ceilings, bring short hooks/tools- and TED/light.
TIP: While handlines are operating in the basement, it's important for members working on the floor above to recognize any signs of hose on the floor above being exposed to fire as to prevent line burn through. Flaked out hoselines placed over registers, open basement stairs with fire below can damage the initial attack line, placing those men in danger. These incidents have already happened numerous times.
In part 2 of basement fires,we will discuss strategy and tactics, hazards and concerns in taxpayers, garden apartments and brownstones.
Good RIT/FAST Training.
Gary Indiana fireman trapped in basement, pulled out through window.
Mayday rescue caught on helmet cam when fireman falls through basement.
The login above DOES NOT provide access to Fire Engineering magazine archives. Please go here for our archives.
Our contributors' posts are not vetted by the Fire Engineering technical board, and reflect the views and opinions of the individual authors. Anyone is welcome to participate.
For vetted content, please go to www.fireengineering.com/issues.
We are excited to have you participate in our discussions and interactive forums. Before you begin posting, please take a moment to read our community policy page.
Be Alert for Spam
We actively monitor the community for spam, however some does slip through. Please use common sense and caution when clicking links. If you suspect you've been hit by spam, e-mail firstname.lastname@example.org.
Check out the most recent episode and schedule of UPCOMING PODCASTS