Over the past few years, wildfires in the urban interface have reached crisis proportions, consuming record amounts of homes each fire season.

Local fire departments have been traditionally equipped and trained to attack fires in homes and other structures. On the other hand, wildland firefighters suppress uncontrolled wildfires by clearing or breaking up fuel so fire can't continue to spread.

It's not surprising that when structural and wildland firefighters arrive at an urban-interface fire, they have different methods for assessing the incident. Often, the local fire department has been called to a house fire to find a wildfire also burning in the area.

STEPS UPON ARRIVAL

How can structural and wildland crews best work together safely and effectively? There's a logical progression of steps that both types of firefighting agencies can take to jointly protect lives and property. These steps, in chronological order, are pre-planning, size-up, structure triage with two-minute walk-around, site preparation, engine company setup and after-fire inspections.

Preplanning

Sizing up an urban-interface fire takes place before the incident ever occurs. An inspection form, such as NFPA 1144, Protection of Life and Property from Wildfire, can be used to collect information on the area. The inspection should include fuels or vegetation types, topographical features, water sources, access, structure types, and defensible space.

Size-up

After arriving at the incident, both structural and wildland firefighters need to make some quick, direct observations. What types of structures are present, and are they constructed from flammable materials? Is there clearance or defensible space for firefighters to work in? Are homes located in steep canyons or close to ridges? Do vegetation and fuels surround the homes? How fast is the fire moving?

Size-up will be an ongoing process throughout the incident, especially when it comes to changing weather and fire behavior.

Structure triage

The quick evaluation of whether a structure can be safety defended from a wildfire helps firefighters decide where they can do the most good with the resources they have on hand. Deciding which homes can be saved and which can't should be a rapid process. Firefighters should need to take only a couple of minutes to walk around a structure to determine if it's defensible. That walk-around should consider if the structure is susceptible, the existence of fuels around the structure, current fire behavior and weather conditions, available resources, and fire safety.

When considering a structure's susceptibility, firefighters should look at the roof to see if it's made of combustible material, such as untreated wood shakes or tarpaper, or of tile, metal or fiberglass, which won't burn. Is the roof flat or pitched? Is there debris on it or in gutters, power lines or overhanging trees? The siding should be checked to see if it's made of combustible wood or vinyl, or of noncombustible metal, brick or adobe. Does the siding go all the way to the ground?

Also look for heat traps such as open gables and unscreened vents and decks. Vinyl soffits will melt and let embers and heat into the attic. Large windows can be an easy entry path for heat and wind-blown debris. Curtains or drapes on the inside can create even more of a hazard. Movable shutters on the outside, however, can be used to shield the windows.

After examining the structure, firefighters should see if there's defensible space or access around the structure that will provide clearance for crews to work safely. Is the yard clear or cluttered? What type of vegetation surrounds the structure? Is firewood stacked against the structure?

When considering the fire's current behavior, responders should check the rate of spread and direction of the fire to determine if there will be enough time to set up and protect the structure. Topographical features can affect the speed of the fire's spread and take away valuable time from firefighter efforts.

Weather conditions also are important. Will wind increase fire spread toward firefighters' position? The longer the flame lengths, the more intense the heat will be when it gets to that location. Are spot fires occurring? If so, they could drop behind firefighters and start new fires that could trap personnel and equipment.

Available resources and firefighter safety are the final components of structure triage. The current and future availability of resources should be considered, as well as their exact location and estimated time of arrival.

In terms of personnel safety, triage should focus on egress and ingress routes. Firefighters need to know the grade and surface conditions of roads, as well as whether they're one- or two-way. In addition, loops or cul-de-sacs may be too narrow for turning large emergency equipment. Other hazards can include heavy fuels or power lines close to the road.

FIREFIGHTING PROCEDURES

If structure triage leads to a decision to commit resources for the defense of a site (see sidebar at left), it's time to move forward with operations.

Site preparation

Conscientious owners may have prepared for an encroaching wildfire, which will make firefighters' jobs slightly easier. Responders should start with the side of the structure that is most threatened by the advancing firefront, accomplishing as many of the following tasks as possible before the fire hits:

• Clear underbrush and other small growth from an area at least three times the expected flame length.
• Turn off LPG tank and put a wet line or clean down to mineral soil around it. Tanks also can be covered with foam about 15 minutes before the fire front hits.
• Turn on yard sprinklers or irrigation system.
• Cut back any trees that touch or overhang the structure.
• Remove attached wooden fences and move woodpiles away from structure.
• Clean off roof and gutters; use the owner's ladder for roof access.
• Move patio furniture inside.
• Close all windows and interior/exterior doors, and close heavy drapes and shades to reduce the radiant heat the reaches the interior.
• Take down flammable awnings and curtains.
• Turn on interior/exterior lights.
• Turn off HVAC system.
• Cover all openings into structure that aren't screened, such as vents and pipes.
• Use the owner's garden hose for roof protection or to refill booster tank.
• Check that private vehicles are in a closed garage or away from structure.

Engine company setup

The engine needs to be positioned in such a manner that a quick retreat can be made if the fire blows up. Here are some guidelines when setting up an engine:

• Back engine into driveway or pull off the road as much as possible without getting stuck.
• Park engine so the structure is between it and the fire front.
• Do not park near or under power lines, flammable trees, LPG tanks and similar.
• Close doors and roll up windows; leave keys in ignition.
• Use 1H-inch hand lines, at minimum, to protect the structure. Use no more than 200 feet per line if possible by pulling lines off the back of engine or hooking up to the pump operator side.
• Have at least 100 gallons of water in the booster tank to protect the engine and operator. Use a 1H-inch line to protect engine.
• Use a nurse, shuttle or dump tank operation. It takes too long to unhook from a hydrant if you need to retreat.
• If you have to retreat quickly, take nozzles only and leave hose.
• Pre-treat site and structure about 15 minutes before fire reaches area.
• Use wet water to pre-treat fuels around structure and Class A foam to pre-treat the structure and any LPG tanks. To coat structure, lob foam onto roof and let it drain down sides.
• If you have a roof fire, check attic for extensions as soon as possible.

After-fire inspections

After the fire front has passed, check structure and surrounding area for hot spots and extensions into the structure. Check all areas, especially the roof and under porches or in crawl spaces.

During a major wildland-urban interface incident, fire protection resources are likely to be overwhelmed. There could be too few of them, or they could be hindered by a lack of access, poor water pressure and more. Also, any resources may be committed to evacuation and rescue and therefore unavailable.

Coordination between responding structural firefighters and their wildland counterparts is essential, and it can be made easier if both crews are familiar with each other's tactics.

Robin Bible has 23 years of experience in wildland fire management and currently is the fire operations manager for the Tennessee Forestry Division.

Ready to commit?

Structure triage will quickly lead to a decision to defend or abandon the structure. Every structure will fall into one of three categories:

• Needs little or no attention: These structures may be in the fire's path but they're not now under direct threat.
• Needs protection but is savable: These structures have a chance to survive if action is taken immediately. This is where firefighters can do the most good.
• Hopeless: If the fire will destroy a structure no matter what's done, it's better not to waste time trying to save them.

Generally, the situation is hopeless when the fire is making significant runs, water supplies are insufficient, the structure is in heavy fuels, the roof or interior rooms are involved, or a neighboring structure is involved.

References

The Firewise program has sponsored and developed reference materials for both firefighters and homeowners to describe the nature of the threat to homes in the interface. These materials can be ordered online at www.firewise.org.

The National Interagency Fire Center has a catalog with ordering information and current prices of all pamphlets, booklets, brochures and videos. Mail or fax orders to NIFC, Attn: Great Basin Cache Supply Office, 3833 S. Development Ave., Boise, ID 83705; fax: 208-387-5573/5548.