Commercial Building Fires: The Attack Line


Size-up of older commercial buildings continues throughout the entire operation. One of your key tactical decisions will involve estimating, stretching, and charging the correct size of attack line on arrival.

Most fire officers, firefighters, and instructors recommend using the 2½-inch attack line on all commercial building fires. When coupled with the 1 1/8-inch or 1¼-inch solid stream tip, the 2½-inch attack line is second to none regarding water flow, reach, and knockdown power. It is not my intention to turn this column into a nozzle debate. The facts are that commercial buildings have a heavier fire load and large undivided showroom areas. These two factors alone are enough reason to warrant a 2½-inch line. Even a contents fire fueled by the high hydrocarbon content used in common materials today can quickly overwhelm a smaller line flowing less water.

Photo 1. This engine company is stretching a 2½-inch preconnected backup line at a commercial building fire. The nozzle firefighter has piled the hose at the back step of the rig and has continued with the stretch, taking only the nozzle. If personnel do not address several key problems prior to charging the line, this line will take a lot longer to put into operation than it should. Two of the most obvious problems are (1) completely clearing the hosebed and (2) properly flaking out the hose in the street or down the sidewalk to assist with the engine company’s advance into a potentially deep commercial occupancy.

1. Photos by author.

Photo 2. This photo was taken approximately two minutes after photo 1. In this photo, the engine chauffeur has realized the potential problems with the hoseline, which he and the nozzle firefighter corrected. The hose that was previously piled behind the engine has been flaked out in the street. Firefighters used an “S” or a “Z” pattern to facilitate a rapid advance into the store. The nozzle firefighter has also positioned several feet of hose directly behind him to assist in the advance.


Although laying out the hose as shown here will certainly work, perhaps a better method may be to flake the hose up and down the sidewalk so that the hoseline will not impede ladder apparatus placement. The worst-case scenario would be a ladder company setting up for the use of the aerial or tower ladder and unknowingly lowering the outrigger onto the hoseline, creating a very efficient hose clamp. If this occurs, both the engine firefighter and the member setting up the ladder apparatus would be at fault for not being aware of the situation.

Regardless of whether or not your department uses preconnected attack lines, every stretch will require estimation. If your department uses preconnected attack lines, you must estimate the stretch to ensure you will have enough hose to reach the seat of the fire. If your department uses a static load hosebed, then you must estimate how many lengths to pull off the bed before breaking the line and connecting the coupling to the discharge outlet.

When estimating a stretch in a commercial building, ensure that you are able to cover the entire occupancy in which you intend to operate. Covering the entire occupancy is important if the fire extends to the cockloft or is later discovered in the cellar. There will be no time to add additional lengths of hose to your stretch when fire is discovered extending above or below you.

To stay out of a short-stretch dilemma, I learned the following simple rule-of-thumb for estimating hose stretches. At a commercial fire, take the depth of the store and double it. With the depth of the store doubled, you will have enough hose if the cellar access is in the rear of the first floor and the fire is in the front of the cellar. In this case, the attack line will need to be stretched to the rear of the store, down the cellar stairs, and then back to the front of the store to the seat of the fire.

Now that the fire occupancy is covered, you must account for the hose that will be used from the entrance door back to the engine. In addition, I always add an extra length to the stretch in case there are several turns, or if the advance must weave through heavy stock or long aisleways. Most engine companies use the standard 50-foot hose lengths. However, some engine companies have one or more 100-foot lengths for various reasons. If you have 100-foot lengths, adjust this rule-of-thumb to work for you.

As involved as estimating the stretch sounds, it is very easy with practice. Most firefighters already perform this estimation at many fires without knowing it. Practice this skill by performing quick drills at your buildings during EMS, carbon monoxide, and other nonfire emergency runs. If time does not allow for a hose stretch, then make the estimate and stretch a search rope to simulate the hose. Mark the rope and measure it when you get back to quarters, to evaluate your skills. If time does not allow for a hose stretch or rope simulation, walk through the estimate in your head or talk through it with other members. Performing these drills will make estimating a stretch second nature.

Photo 3. This engine company has prematurely started water in the hoseline. The hose was not properly flaked out as in photo 2. Members will have to work twice as hard to remove the kinks; flake out the line; and, in some cases, remove knots in the hoseline. If this is the first hoseline at an incident, the fire will have more time to spread, and the building might be untenable when the line is finally ready to advance. Had this been a second line, the first line’s crew or members conducting a search might have been placed in a precarious position, since their protection would have been severely delayed.


In many cases, abandoning this line and starting to stretch a new line might be your best option, depending on the situation and severity of the “spaghetti” in the street. To avoid this situation, make sure that when the line is stretched, someone looks at the layout and path that the dry line takes to the nozzle team. Although it is every engine firefighter’s responsibility, many departments assign a member to this important task of ensuring the line is laid out correctly and all of the kinks are removed after the line is charged, before entering the building.

However your department chooses to perform this task, it must be done. Take the time early in the incident to properly stretch and flake the hose. This will ensure that a smooth advance to the seat of the fire will be unimpeded by pressure or water loss caused by kinks that can result in injured firefighters. Additionally, it will be easier for engine firefighters to feed hose into the building. This will result in an efficient advance and faster fire knockdown. Take time to make time!


Here are some questions and comments for the kitchen table. Discuss them at a drill and see what answers you come up with.

  • If the fire occupancy type is not obvious on arrival, what actions can be performed to assist you in locating the fire store?
  • The building in photos 1 and 2 is a self-service laundry. What are some hazards commonly associated with a self-service laundry in these older type commercial buildings?
  • If you do not already stretch 2½-inch attack lines regularly, discuss how your unit or department might get a 2½-inch attack line in operation.
  • In photo 2, what other hazards or size-up points can you bring up for discussion?
  • In photo 2, the windows are Plexiglass® or Lexan®. Which tools would you use to defeat these windows?

Author’s note: If you have photos that Fire Engineering can use in this column for a positive learning experience, please send them to Please include your full name and a detailed description of the incident.

NATE DeMARSE is a firefighter with the Fire Department of New York. He and his brother Curtis own Brotherhood Instructors, LLC.

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