Protecting Exposures

Photo by John J. Salka Jr. These two private houses, although not attached, are so close that the eave overhangs the house next to it. Any fire that vents through a window in this narrow opening will rapidly extend to the wood or asphalt siding and race to the top, where it could quickly enter both buildings and attic area.

Several situations can result in a fire extending into an adjoining or exposed building. When these situations are encountered, a decision must be made immediately as to whether to take action in that direction and, if so, what specific tactics to employ. It is at this moment that the outcome of the entire operation may be decided.

If an exposure is in danger of extension and the fire department's attack is directed to the original fire building, it may result in a multi-building extra-alarm fire. If the fire is not extending to an exposure and the fire department chooses to concentrate its resources on preventing this possible extension rather than making an offensive attack on the fire building, the fire within the original fire building will grow unchecked and result in more serious fire damage that may have been prevented.

The conditions that generally indicate exposure protection as the primary tactic at a structural fire are advanced fire conditions on arrival (fully involved) adjacent to other structures, fire which has self-vented through windows facing an adjoining structure and heavy fire conditions in attached/ connected buildings. Depending on a department's apparatus and equipment, staffing and water resources, several tactics can be initiated to protect endangered exposures.

One of the most versatile and effective methods of protecting exposures is the stretching and operation of a 2 1/2-inch handline. The importance of using the larger 2 1/2-inch hose rather than 1 1/2-inch or 1 3/4-inch cannot be overstated. Both the 1 1/2-inch and 1 3/4-inch handlines were developed for offensive interior firefighting where firefighters had to negotiate through small rooms and hallways and the fire load was limited to the contents of one or two rooms. The larger 2 1/2-inch line, which was once the mainstay of most fire departments attack lines, both interior and exterior, delivers a greater flow of water with increased reach and penetration. These advantages although tempered by difficulty in maneuverability and advancement, make this large handline the best choice for protecting exposures.

With a flow of 250 gpm and excellent stream reach, the 2 1/2-inch line can deliver a large amount of water to a wide area in short order. Because it is a handline, it can be maneuvered to cover several exposed sides of a building or even repositioned to cover another exposed building. It can be stretched down alleys or driveways to rear yards and can also be operated from adjoining rooftops and setbacks. Since most engine companies carry a bed of 21/2-inch hose with a nozzle attached, it can be stretched and put into operation quickly by one or two firefighters without the delay that would be incurred by setting up and connecting hoselines to a portable deluge gun or multi-versal nozzle.

Another method of protecting exposures is the use of the apparatus-mounted deck gun. These appliances are referred to by many names such as deck pipe, stang, deluge gun, etc., but the principle is the same. Here we are talking about a master stream which is generally considered to deliver more than 300 gpm. Whether the appliance is permanently piped into the apparatus or is secured in a usable position on the engine, it can be placed into operation relatively quickly and will deliver substantial knockdown to an extending fire.

Advantages of this appliance are that it can be operated by one firefighter with little fatigue and applies even more water to greater distances than the 2 1/2-inch handline. A major disadvantage of the apparatus-mounted deck pipe is that its effectiveness relies greatly on the position of the engine apparatus. Depending on what other fire extinguishment tactics are being employed such as handlines being stretched and hydrant connection, the engine apparatus may not end up in the most advantageous position for effective use of the deck pipe. In the case of closely situated structures with narrow driveways or alleys between them, positioning the apparatus just several feet beyond or before the space between the buildings may prevent its use.

Photo by John J. Salka Jr. A portable master stream device is operated to protect a building which is being exposed to severe radiant heat from a large, heavily involved commercial structure. Directing water into the air between buildings to protect exposures has been proven ineffective. Direct water application onto the threatened structure is the best way to prevent extension.

A good rule to follow when it is obvious that an outside stream will be required to protect an exposure is to position the apparatus for that operation. If a handline is required, it can still be stretched off the hosebed. It may even require several more lengths to reach its objective, but both tactics will be initiated without negatively affecting the other.

The third tactic for protecting exposures is the use of portable master stream appliances. These devices possess many of the same features as the piped in deck gun but can be removed from the apparatus and placed in remote positions. The obvious advantage here is that we can place an appliance capable of delivering more than 300 gpm anywhere around or between the fire building and the exposures. This provides for effective exposure protection and at the same time the stream can be alternated between the exposure being protected and the original fire building which is threatening the exposure.

The disadvantages of portable large-caliber streams is that they must be transported to the intended area of operation, supply lines must be stretched and they usually must be secured with a utility rope to prevent movement. To complete these duties an entire engine crew will usually be required and it could take five to 10 minutes before water is started.

Ladder company large-caliber streams such as ladder pipes, both pre-piped and portable, and basket mounted streams can also be used to protect exposures. The capability to elevate and extend the stream above and around the fire building and its exposures increases the effectiveness of these streams and allows for almost pinpoint accuracy.

The use of ladder company apparatus for exposure protection is usually a secondary consideration because the 2 1/2-inch hoseline, the apparatus-mounted deck pipe and the portable large-caliber stream can be quickly placed into operation by an engine company operating independently. At large-scale, multi-building fire operations, ladder company large-caliber streams often are used as a last resort in the "surround and drown" mode.

Proper selection and use of these tactics and appliances can make the difference between a single-structure fire and a multi-building operation. Firefighters must train on setting up, supplying and operating these devices. When an outside stream is needed for exposure protection, it must be set up and placed into operation quickly to limit the travel of the extending fire. Both chief and company officers must be aware of the situations that require the use of these protective streams and must not hesitate to order their use when appropriate.

Using outside streams to confine a structural fire to the building of origin is often looked upon by members of the fire service as a sign of retreat and even defeat. We know this is true in some cases but in many others a knowledgeable company officer or experienced chief has ordered an outside stream into operation to protect an exposure and has been criticized and second-guessed at the scene but praised and credited with "saving the block" the next day.