Command and control ics chapter 9

Vacant Commercial Buildings: An Overview

• Defined as unoccupied structures previously used for manufacturing, warehousing, or sales.
• Designs vary from single to multi-story, ranging in size.
• Vacancy reasons include business failure, demolition plans due to age/condition, waiting for new occupants/renovations.

Occupancy-Specific Cues

• Includes special construction factors, wall/roof/floor construction, influencing fire loading/spread.

Special Construction Factors

• Construction types in vacant commercial buildings can range from noncombustible to wood frame.
• Mixed construction types are common, especially in older buildings modified over time.
• Buildings have deficiencies affecting fire spread and structural stability
• Buildings with old-style construction, minimal fire resistance, and lack of built-in fire protection pose significant fire risks.
• Buildings generally have ordinary construction (masonry walls with wooden floor and roof assemblies).

Wall Construction

• Walls can be masonry (concrete block, brick), tilt-up concrete, metal, or a combination.
• Multistory structures might have steel frames with curtain walls.
• Wood-frame walls are usually platform type, limiting vertical fire spread.
• Fire walls or fire-division walls separating occupancies are beneficial but rare.
• Wall collapse is a significant risk, often triggered by failure of other structural members (e.g., roof).
• Safety officers should monitor structural deterioration.
• Wall coverings (e.g., cork in food-processing plants) can increase fuel load and smoke.

Roof Assemblies

• Roofs vary with age, design, and construction type.
• Older buildings often have flat roofs with wood beams, rafters, and sheathing.
• Newer structures may feature steel bar-joist roofs, prone to rapid failure (as little as 9 minutes).
• Parallel-chord wood truss and wooden I-beam roofs are typical in modern construction.
• Panelized roofs on tilt-up buildings are dangerous during fires due to minimal support.
• Pitched roofs can be ridgepole-and-rafter (older) or wood-truss (nailed or gusset plate).
• Arched roofs (bridged-truss or bow-string) are common in large-area buildings.
• Bow-string roofs are known for collapse, especially with added weight on the bottom chord.
• Cast iron lally columns supporting roofs can shatter when cooled rapidly, leading to roof failure.

Fire Loading and Fire Spread

• Fire loading depends on building conditions: minimal (cleaned out), medium (some debris), or maximum (large amounts of combustibles, unsecured).
• Delayed alarms are common, leading to major fires and potential structural damage.
• Rapid fire spread can occur due to combustibles, open spaces, and building deficiencies.
• Decay, vandalism, and transient activity contribute to fire spread.
• High risk of incendiary fires due to vagrants or insurance fraud.
• Incendiary fires often have multiple origin points.

Floor Assemblies

• Floors can be beam and joist with wood decking (older) or concrete (newer).
• Multistory buildings may have concrete first floors, with beam and joist floors above.
• Trussed joist floor assemblies are also common.
• Floor voids require caution during interior operations.
• Loss of floor supports can trigger wall collapse, especially in older buildings with unreinforced masonry.

Common Problems

• Preplanning and size-up are essential for assessing fire involvement, structural deterioration, and collapse potential.
• Awareness of exposures and access points is crucial.

Roof, Wall, or Floor Assembly Construction Type

• Identification of construction types is critical during preplanning.
• Assume lightweight construction if unable to determine the construction type of building elements involved in fire, and act accordingly.

Fire-Involvement Considerations

• Determine fire location and extent upon arrival.
• Assess fire spread potential (volume, paths, location).
• Avoid endangering personnel with offensive tactics if the building is lost.
• Check for fire extension into attic areas.
• Determine if the fire is affecting structural components.

Structural Deterioration and Collapse

• Consider structural deficiencies in safety and fire attack methods.
• General decay or modifications affect fire development.
• Buildings scheduled for demolition should be approached defensively.
• Rapid structural deterioration can occur due to fire intensity and spread.
• Roofs are typically the first elements to fail, with trussed roofs being most vulnerable.
• Anticipate roof collapse after prolonged fire exposure.
• Wall collapse can be gradual or sudden and is influenced by roof construction.
• Roof loss often precedes wall failure, affecting stability.
• Direction of wall collapse is unpredictable; walls may fall inward or outward.
• Walls in heavy timber or ordinary construction tend to fall outward.
• Safe distance from walls should be at least one and one-half times their height.
• Floor collapse can result from fire or walls pulling away.
• Remove firefighters from unsafe buildings and surrounding areas.

Exposures

• Exposures are either connected or unconnected.
• Connected exposures are difficult to protect due to proximity, requiring protective lines.
• Unconnected exposures are easier to protect due to distance, allowing for exterior hose streams.

Access Points

• Access points are critical for reaching the fire area.
• Preplans should identify access points.
• Secured buildings may delay entry, increasing fire control difficulty.
• Truck company operations are essential.
• Select access points that avoid driving fire into uninvolved areas.

Cue-Based Predictions

• Assume a defensive mode for significant fires.
• Prioritize apparatus placement, exposure protection, and water supply.
• Pessimistic view of structural integrity due to potential collapse.
• Establish collapse zones early.
• Suspect arson and plan accordingly.
• Master streams and large handlines are often necessary.

Incident Management Cues

• Fires often require multiple coordinated tactical operations.
• Failure to coordinate can lead to ineffective control and injuries.
• Command officers must ensure timely and non-conflicting tactics.

Strategy and Tactics

• Perform a thorough size-up considering construction, deficiencies, failures, fire location/extent, behavior, and resource needs.
• Base strategy on risk vs. benefit analysis, considering life safety and building value.
• Use defensive tactics when the building is mostly damaged or scheduled for demolition.
• Prioritize exposures, starting with occupied and connected ones.
• Offensive or defensive attack depends on fire conditions and resources.

Offensive Attack

• Attempt to extinguish the fire and save the building.
• Only use when it is safe to enter the building.
• Continuously monitor fire location, size, and structural stability.
• Use larger diameter (21/2 inch) handlines for increased safety and reach.
• Assign backup teams with charged hoselines.
• Monitor personnel location and status.

Defensive Attack

• Extinguish the fire without entering the building.
• Protect exposures with hose streams.
• Exercise caution when mixing hand-held lines and heavy stream equipment.
• Consider initial apparatus placement for potential master-stream use.
• Initial strategy may be defensive, switching to offensive upon resource arrival.
• Communicate changes in attack mode clearly.
• Ensure personnel stay back from walls.

Alarm Signal

• Use a common signal (e.g., air-horn or dispatcher-generated wail) to indicate the need for immediate evacuation.

Summary

• Incident Commanders use occupancy-specific cues from wall/roof/floor construction that affect fire load and fire spread.
• Preplanning and size-up consider structural deterioration and collapse potential as well as exposures and access points.
• Response includes an alarm signal for life safety and assessing offensive and defensive attack options.