Fighting Fires in Crawlspaces

It is six o’clock in the evening on a cold winter’s night, and your company is called to an odor of smoke on the first floor of a two-story wood-frame duplex. There is nothing apparent from the exterior, and a search of the residence reveals an odor of burning wood and light smoke coming from a light fixture in the kitchen ceiling. After you secure the circuit breaker and remove the light fixture, smoke is steadily emitting from the hole even though no fire or charring is present. You pull the gypsum board back, and there still is no evidence of fire or charring. Where is the smoke coming from? You check nearby appliances and outlets. Nothing.

A firefighter is directed to check the home from the exterior. On removing the crawlspace hatch, he is met with heavy smoke and fire. A 1¾-inch line is quickly stretched, and the fire is knocked down from the crawlspace hatch. During overhaul, your crew discovers the original smoke condition was caused by smoke that was escaping up a pipe chase from the crawlspace.

Has this situation ever happened to you? This was the exact scenario of the first fire to which I responded in 1998. We obtained a thermal imaging camera a few years later, but this luxury was unavailable at the time of the incident.

When the fire originates in the crawlspace, it can create some operational challenges that force us to implement tactics we do not usually employ in our routine playbooks. This article provides some experienced-based strategy and tactics that have worked for me over the years.

This fire in a crawlspace occurred in a balloon-frame duplex in Mount Holly Township, New Jersey, in February 2018. This was a natural gas-fed fire from a ¾-inch flexible gas line that was compromised by fire. The gas line ran from the full basement of the original foundation of the residence to the additions in the rear. Note the changes in the roof line and exterior building material where the two additions were located. (Photos by Lieutenant Bryan Iannacone.)

(1) This fire in a crawlspace occurred in a balloon-frame duplex in Mount Holly Township, New Jersey, in February 2018. This was a natural gas-fed fire from a ¾-inch flexible gas line that was compromised by fire. The gas line ran from the full basement of the original foundation of the residence to the additions in the rear. Note the changes in the roof line and exterior building material where the two additions were located. (Photos by Lieutenant Bryan Iannacone.)

Construction Features of Crawlspaces

Crawlspaces are very common across the country. They have existed in a variety of residential and commercial buildings, mostly in Type 5 (wood frame) construction, over a broad range of eras. Crawlspace heights can range from just a few inches to a couple of feet off the ground. They are a regular staple in the area in which I live—a shore community just a few feet above sea level; hence, the water table is too high to excavate for basements. In addition, I have encountered crawlspace fires in the community in which I work, 25 miles outside of Philadelphia.

It is extremely common to have a balloon-frame home with numerous additions. Though typically found in the rear, these additions with crawlspaces underneath can exist on all sides of the structure. They were often constructed when indoor plumbing for a new bathroom or kitchen was being introduced into the house. One clue to help you determine the age of the house is the presence of exterior cast iron soil pipes running the height of the exterior from the roof to the ground. These additions could be just one story or the full height of the structure. Depending on the builder or other alterations, these additions may or may not be openly connected to the basement. Voids, ductwork, pipe chases, and other utilities may be present with no fire stops into the adjoining basements or floors above. Hidden fire can spread in these concealed, combustible spaces and go unnoticed.

One beam of the floor in the kitchen over the origin of the fire was removed to gain access for overhaul. The initial attack line was stretched to the interior, and the second line was stretched to the exterior.

(2) One beam of the floor in the kitchen over the origin of the fire was removed to gain access for overhaul. The initial attack line was stretched to the interior, and the second line was stretched to the exterior.

When conducting a 360° size-up, look for changes in the foundation’s cinder or concrete blocks. A change in the color, style, or size of the blocks can indicate a separation from one section of the crawlspace or basement to another—for example, the original structure is stucco on wood frame, and the addition is concrete block and stucco. This can present a challenge when trying to use the reach of the hose stream from the crawlspace hatch to the seat of the fire. A block foundation wall from the structure’s original footprint could block the reach of your stream.

In shore areas, homes and commercial buildings are built on wooden pilings. In this case, the exterior wall may be covered with plywood or breakaway particleboard. Here, you have an advantage: You can easily breach these walls to gain access to the fire. On the other hand, this type of construction creates a disadvantage: The carriage bolts connecting the pilings to the beams can become very hot when attacked by fire, and they will remain hot for some time. This can cause a rekindle under the right conditions, so monitor and cool these carriage bolts during overhaul.

Access hatches vary according to the builder. Typically, there will be at least one access hatch from the exterior, usually at the rear of the home. Do not confuse access hatches with ventilators, which are only the size of a regular concrete block. In the winter, most ventilators are stuffed with insulation or covered with wooden hatches to prevent pipes from freezing. Access hatches can commonly be found on the interior as well, either from a basement (if there is one) or in the center of the home where a floor furnace was once housed.

Size Up the Situation

The crawlspace fire you are called to may not be hidden as the one described in my first experience. More than likely, charged smoke will be pouring from the ventilators or the first floor of the home. Like all incidents to which we respond, a good 360° size-up from the exterior and another size-up on the interior conditions will determine the fire’s location and extent. The thermal imaging camera can greatly enhance your size-up abilities; you should use it throughout the incident.

The exterior lap siding was then removed with chain saws to gain access. The reach of the stream from the second line on the exterior successfully knocked down the fire once the free-flowing natural gas was shut off.

(3) The exterior lap siding was then removed with chain saws to gain access. The reach of the stream from the second line on the exterior successfully knocked down the fire once the free-flowing natural gas was shut off.

While sizing up, locate the access hatches and make educated decisions on where to stretch the initial and second attack lines. If you stretch the initial attack line to the exterior access hatch, you must stretch a line to the interior in case there is extension. Balloon-frame homes will necessitate additional personnel, as the fire can quickly run from the basement to the attic. Call for additional companies early in the incident if you suspect a personnel-intensive operation on gaining access and checking for extension.

Expect fire extension into the spaces above the crawlspace. Again, ventilation ductwork, pipe, and other utility chases can be present and will easily spread fire. Fires in crawlspaces tend to burn for an extended time because they are below where the occupants are.

Incendiary Fires

Accelerant poured on the floor can drain down into the crawlspace, resulting in a fire running the bays—the space between the floor joists. The fire will extend horizontally in the bays until it finds plumbing; electrical; or heating, ventilation, and air-conditioning—anything that will allow it to extend vertically in the walls and eventually find its way to the attic. Fires in crawlspaces necessitate an immediate examination of kitchens and bathrooms, where fire can follow plumbing pipes. As always, if you observe irregular burn patterns on the floor that could indicate an incendiary fire, keep personnel from disturbing the area to preserve evidence for the fire investigator.

Life Safety

Life safety is our number-one priority, and we must conduct a search to ensure all the occupants are out of the fire building. Fleeing occupants or contractors working on the home can also provide vital information pertaining to the fire’s location, so listen, but verify their report. At a crawlspace fire to which I responded several years ago, an elderly woman was trapped in the bedroom with fire coming up through the floor in the hallway, where the floor furnace was on fire. A quick-acting police officer jumped over the flames and rescued her just prior to our arrival. Remember that it doesn’t take a good fire blowing out the windows on arrival to have an immediate life threat. Complacency kills, and no fire is routine.

The crawlspace hatch was in the rear of the home and was connected to another crawlspace hatch between the additions. The rear door shown led into a bedroom, which was connected to a bathroom, adjacent to the kitchen.

(4) The crawlspace hatch was in the rear of the home and was connected to another crawlspace hatch between the additions. The rear door shown led into a bedroom, which was connected to a bathroom, adjacent to the kitchen.

Strategy and Tactics

As I think back on fires that I have commanded, one that went very smoothly comes to mind. I ordered the initial attack line to be stretched to the three-foot-high exterior crawlspace hatch where we had visible fire and, simultaneously, the second line to the interior. Once inside, the engine company found a room-and-contents fire that was not initially visible from the exterior. The fire had traveled up the ductwork and into a bedroom on the first floor. This attack worked extremely well because I had enough firefighters on scene to quickly make it happen with two lines and conduct a primary search. The key is to have adequate and reliable resources on the initial dispatch following alarm assignments, which should be competently thought out.

Typically, you can get a good knockdown of the fire with the reach of the stream from the access hatch. A smooth bore nozzle will provide better stream reach and penetration for this type of operation. Certain construction features and voids will cause us to occasionally pull out one of two specialty nozzles—the piercing nozzle and the Bresnan distributor nozzle. Place these nozzles directly over the seat of the fire if the floor integrity allows you to do so. Lightweight trusses and I-beam floor joists may prohibit you from doing this, so sound the floor from the doorway you entered, and work from a safe area.

If Access Is Restricted

What if there is no access hatch or if access is restricted? An option for concrete blocks with hollow cores is to strike the blocks using a sledgehammer; however, this can quickly tire a crew. One tactic we have used several times over the years is to make our own access hatch in the floor, usually about three feet by three feet, with the chain or rotary saw. A battery-powered reciprocating saw can be helpful here once you have made a purchase point. The trick to this tactic is placement.

If you attempt to cut a floor covered in carpet, the saw will bind up (we made that mistake). Cutting the carpet with a utility knife is an option, and it has worked. A quicker option is to go to the kitchen or any room with a linoleum floor and make your cut to create an access point. Removing one of the floor joists in the center of the hole is usually sufficient to make enough working space without seriously compromising the floor’s integrity.

Once the fire is knocked down, we usually have the smallest firefighter (usually me) go down the hole and finish the job. I would not advocate sending a firefighter into a crawlspace or any confined space under heavy fire conditions. Work from a safe distance using the reach of the stream or a specialty nozzle, and get the fire under control first.

Overhaul

When operating inside the crawlspace during overhaul, it will most likely be filled with water, mud, fallen fiberglass insulation, or wiring, so use caution. After lying or crouching down in these conditions, decontaminate your turnout gear on scene, and then wash it fully back at the firehouse. We should be washing our turnout gear after every fire, but crawlspaces are particularly unpleasant locations in which to work. I spent a decent amount of my life in crawlspaces helping my father, a master plumber, with his work, and I can attest to this.

Discuss this topic with your crew, and share experiences. If your department does not regularly deal with crawlspace fires or if it has been a while since you went to one, ensure that everyone is familiar with the strategy and tactics that may be used. Although fighting a crawlspace fire is mostly an engine company operation, make sure that you thoroughly check for fire extension. Above all, conduct an aggressive primary search, and save lives!


Michael P. Wolfschmidt is a career firefighter/EMT in Westampton Township, New Jersey, where he coordinates the training for the department. He is a fourth-generation firefighter and a past chief and life member of the Surf City Volunteer Fire Company, where he began his career as a junior firefighter in 1998. He also works per diem as a deputy district fire warden with the New Jersey Forest Fire Service and a level 2 fire instructor at the Ocean County Fire Academy.

Originally ran in Volume 173, Issue 1.

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