OTTAWA FIRE SERVICES
LESSON PLAN
Subject: / Strategies and Tactics –Type IIPrerequisite: / Fire behavior, IMS / Accountability, Ventilation, Water supply, Fire Tactics Intro,
Fire Tactics 1
Learning Outcomes: / The firefighter will;
Understand type 2 construction
Know the tactical principles for type 2 buildings
Understand the importance of size-up
Understand duties of responding personnel
Understand the common automatic protection
Understand the common types of occupancies
Time: / 2 hours
References: / OFS Strategy and Tactics Manual (issue: June 15, 2010, revision November 8th 2010)
Teaching Aids: / OFS Strategy and Tactics Manual, White board, Projector and Screen
Safety Considerations / N/A – Classroom Setting
Slide #1 / Introduction
Type II structures vary in size, configuration, occupancy, and fire load. Type II construction issued for
• strip malls and warehouses,
• grocery stores and big box stores,
• school gymnasiums and hockey arenas, and
• business and industrial parks.
While commonly referred to as non-combustible, Type II buildings do not resist collapse and firespread to the same degree as Type I buildings. A good rule of thumb for identifying thesestructures is that they tend to be no more than four storeys in height and usually have exposedsteel roof joists.
Ottawa has many urban, suburban, and rural areas where Type II construction is prevalent. Manyof Ottawa’s business parks are comprised of one and two storey buildings that are mainly Type II. This training identifies Type II features and physical characteristics, and outlines theprocedures and operational requirements for dealing with fires in this type of construction.
Presentation
Slide # 2Slide # 3
3.1.3
Slide # 4
Slide # 5 & 6
Slide # 7
3.1.4.
Slide # 8
3.1.4.
Slide # 9
3.1.4.
Slide # 10
Slide #11
Slide #12
3.1.5.
Slide # 13
3.1.5.
Slide # 14
3.1.5.
Slide # 15
3.1.6.
Slide # 16
3.2.1
Slide # 17
3.2.1.
Slide # 18
3.2.1.
Slide # 19
3.2.1.
Slide # 20
3.3
Slide # 21
3.3.2.
Slide # 22
3.3.2.1.
Slide # 23
3.3.2.1.
Slide # 24
3.3.2.1.
Slide # 25
3.3.2.1.
Slide # 26
3.3.2.1.
Slide # 27
3.3.2.1.
Slide # 28
3.3.2.1.
Slide # 29
3.3.3.
Slide # 30
3.3.4.
Slide # 31
3.3.4.
Slide # 32
3.3.6
Slide # 33
3.3.6
Slide # 34
3.3.5
Slide # 35
3.3.7.
Slide # 36
3.3.7.
Slide # 37
3.3.7.
Slide # 38
3.3.8.
Slide # 39
3.4.1.
Slide # 40
3.4.2
Slide # 41
3.4.3
Slide # 42
3.4.5
Slide # 43
3.5
Slide # 44
3.5.1
Slide # 45
3.5.2
3.5.3
Slide # 46
3.5.4
Slide # 47
3.5.5
Slide # 48
3.5.6
Slide # 49
3.5.7
Slide # 50
3.6
Slide # 51
3.7.
Slide # 52
3.7.1
Slide # 53
3.7.2
Slide # 54
3.7.2
Slide # 55
3.7.3.
Slide # 56
3.7.3
Slide # 57
3.7.4
Slide # 58
3.7.5.1
Slide # 59
3.7.5.2
Slide # 60
3.7.6
Slide # 61
3.7.7 / Objectives
- Understanding type 2 construction
- Responding to type 2 buildings
- Tactical principles for type 2 buildings
- Size-up
- Duties of responding personnel
- Automatic protection
- Common types of occupancies
In Type II construction, also known as non-combustible construction, the structural components can be protected or unprotected.
In unprotected construction, the structural elements are non-combustible,but have no fire resistance rating. The use of unprotected steel is the most commoncharacteristic in unprotected, non-combustible construction. An example of this is the use ofunprotected steel columns or steel beams for roof support.
Type II construction differs from Type I fire-resistive construction in that Type II building tend to be lower and are not designed for residential use. The most common height of Type IIbuildings is from one to three storeys.
Unprotected Structures
Example of unprotected structures is the use of exposed steel columns or steel beams for roof support
Typical construction used for mercantile commercial type buildings.
Protected Structures
Structural steel elements frequently have a degree of fire resistance that is less than what isrequired for Type I construction. When this is the case, these structural elements can be coveredwith fire resistive material or encased in fire resistive insulation.
Fire resistance refers to the ability of a structural assembly to maintain its load bearing ability under fire conditions. Non-combustible, a misleading term, refers to the fuel contributed by the structural components, not its resistance to fire spread. Type II construction has structuralcomponents that may or may not have a fire resistance rating.
Use of fireproofing material to give the steel a fire resistance. The type of fireproofing and thickness applied dictates the degree of fire resistance provided.
When protected in this fashion, Type II structures are referred to as protected non-combustible construction.
If the building is equipped with sprinklers in areas where there are exposed steel
elements, that area can also be considered protected.
Figure in this slide depicts a typical Type II building under construction.
It has load-bearing steel columns supporting a lightweight steel joist assembly.
Long steel I-beams run perpendicular to the roof joists and are supported by the columns.
The joists are often left exposed and unprotected from the underside.
The I-beam is also exposed and supported by steel columns that transfer the weight of the roof down to the footings.
Open-webbed joists are available in various depths and spans of up to 44 metres.
Depending on the occupancy, interior finishing, and fire load, during a fire these steel load-bearing elements must be cooled to prevent collapse.
As with Type I construction, the structural members in Type II construction contribute little or no fuel load.
However, buildings classified as Type II often do not meet the strict definition.
Combustible construction materials are sometimes used in Type II buildings, example can be the roofing material.
Loads and Connections
In Type II buildings, loads are transferred from the roof to load-bearing, non-combustible columns or walls to the foundation. As it is with all structures, the way the different building elements are connected dictate the building’s overall stability.
There are two common types of connections in Type II construction:
• With pinned connections, elements are joined with simple connections such as bolts, rivets, or welded joints. These are usually not strong enough to re-route forces if one member is removed or fails.
• Rigid-framed connections, as illustrated in next slide, are strong enough to re-route forces if a single member is removed.
Rigid Framing
Rigid framing is designed to resist the bending forces resulting from the supported loads and lateral forces.
In a building constructed with rigid-frame connections, sufficient rigidity exists between the beam and the column so that no change occurs in the angle between the beam and the column as loads are applied.
Protected, non-combustible construction provides a degree of structural stability, depending on the degree of fire resistance provided.
An unprotected, non-combustible building will not provide prolonged structural stability under fire conditions.
To prevent firefighter safety from being compromised, the Incident Commander should anticipate failure of unprotected steel because of excessive heat.
Failure of Type II Construction
The point at which unprotected members fail will depend on the following factors:
• Ceiling height of the building;
• Dimensions of the unprotected members;
• Intensity and duration of the fire and heat exposure; and
• The load stress on the unprotected steel.
Figure on this slide shows a Type II structure under construction where the roof load is supported by concrete block load-bearing walls.
The steel column supports an open web beam supporting roof joists, which are pinned to the top chord of the beam.
This is not a rigid-frame design in that the bottom chords of the roof joists are shorter than the top chords and are unattached.
This design allows the bottom chord to expand and twist without exerting horizontal pressure on the load-bearing elements.
Characteristics
The structural components of Type II buildings
• are usually steel or concrete;
• do not add to the fire load; and
• have some or no degree of fire resistance, depending on use and occupancy.
Type II buildings are constructed either with a steel frame or concrete load-bearing walls.
If constructed with a steel frame, they can have either metal or non-load-bearing concrete block exterior wall.
There is a serious risk of early collapse of typical Type II buildings. These buildings are not structurally stable under fire conditions and failure of unprotected steel should be anticipated.
Steel members can fail at as little as 426.66° C (800°F). When heated, steel beams and joists will expand, pushing out walls and creating a potential for load-bearing wall collapse.
Characteristics
•Combustible materials permitted.
•Fire loading based on occupancy.
•With or without sprinkler protection.
•HVAC typically mounted on roof.
•Large open space.
Combustible materials can be used in Type II construction for interior finishes, roof coverings and structures, exterior veneers and trim and nailing strips.
Depending on the occupancy type, fire loading will vary and the building may have sprinklers.
Heating, ventilation, and air conditioning (HVAC) equipment is usually located on the roof.
Basements, although not common, can exist. Type II buildings can have a large building footprint and large open spaces within them.
Combustible Roofing Material
Type II buildings are usually constructed with a flat, metal deck roof supported on open-webbed steel joists.
Roof composition is commonly combustible metal deck roofing, which is referred to as built-up roofing.
It is comprised of a waterproof cover, rigid insulation, and corrugated metal decking.
Many roofing systems, on Type II non-combustible buildings include fibre-board and polyisocyanurate (polyiso) combustible foam board insulation, which adds to the building’s combustible load.
Responding to Fires
Combustible Roofing Material = Early Failure
The roofs of warehouses built before 1970 can be comprised of layers of tongue and groove boards over steel roof joists.
The boards are layered to be several centimetres thick and provide the basis for the roof deck.
Many of the warehouses on Holly Lane in Ottawa’s south end have roof assemblies like this.
Fire companies might have time to properly ventilate these roofs vertically if the fire has not taken hold of the roof itself.
The weight of HVAC systems must be kept in mind.
Many older Type II and III buildings have had modifications for HVAC and venting systems for kitchen exhausts.
In some instances, the roof structure might not be engineered for the added load.
Responding to Fires
Roof Bowed by Heat Exposure
These open-webbed, unprotected bar joists can fail in as little as 5 to 10 minutes of intense fire exposure.
Figure on this slide shows open-webbed steel roof joists that are bowed because of exposure to heat.
Responding to Fires
The combustible roofs create a serious problem for fire spread.
It is not advisable to place firefighters on these roof structures if a significant fire is burning.
As a steel roof deck heats, the tar and foam insulation on top of the deck liquefy, they migrate into the channels of the steel decking and flow under unburned material.
Once exposed to air, the material ignites, spreading fire from the area of origin to remote areas.
Tactical Principles
•Forcible Entry
•Locating the Fire
•Using Master Streams
•Managing Air Supply
•Advancing Hose Lines
•Ventilation
•Hazards and Safety
We will now outline the strategies and tactics required for fighting fires in Type II structures.
The information is based on the latest North American research pertaining to fires in these types of buildings.
As with other types of building design, there are unique aspects to Type II construction that require specific treatment. From big box stores to small garages, Type II buildings present unique challenges to fire personnel.
Type II structures are present in just about every area of Ottawa and have a wide variety of occupancy with various fire loads. While primarily used for commercial and manufacturing use,
Type II structures are also used for office space, medical offices, and even restaurants.
Forcible Entry
Rule 1: Try before you pry. It is inexcusable to have a crew go through the entire
forcible entry process only to find out that the door was unlocked.
Rule 2: Don’t ignore the obvious. Look for the easiest way to get in. There is
often more than one entry point into a structure. Depending on the urgency of the situation and the purpose for forcing entry, all options should be considered
before you undertake to gain entry forcibly.
Rule 3: If possible, use the door that the occupants normally use to enter or exit
the premises. Not only does this place you in the occupants’ most likely path of
egress for rescue purposes, it also makes your task much easier.
Rule 4: Maintain the integrity of the door. In other words, keep the door intact.
One of the least desirable methods of forcible entry is to smash open a plate glass
door or window, even if it is obvious that a serious fire is burning. This approach
can create the circumstance for a backdraft, as the sudden in-flow of fresh air can cause the triggering mechanism for a significant fire event.
Forcible Entry Methods
Figure shows where bolts for the panic bar are located and how these bolts can be cut using a circular saw.
This method allows for the removal of the panic bar from the exterior.
However, it is time consuming and may also require the removal of the deadbolt lock.
Forcible Entry Methods
One of the most effective methods of defeating a deadbolt lock in a steel frame is to tap door wedges in the space between the door and the frame approximately 15-20 centimetres above and below the location of the lock.
The wedges will expose the deadbolt sufficiently so that it can be cut using a circular saw blade.
See the diagram on this slide.
Forcible Entry Methods
Figure on this slide shows a rotary saw being used to cut a deadbolt lock on a double hinged door assembly.
This method is the least destructive way to gain entry and leaves the door intact so that it can be used to control air flows and pressure.
It also allows the building owner to effectively secure the building after the incident by simply replacing the lock.
Forcible Entry Methods
Figure on this slide shows how a triangular cut can be made to defeat a bar jam.
This type of cut allows a firefighter to reach in and release the panic bar and remove the steel jam.
This should only be done if interior conditions permit, as it would be inadvisable for any firefighter to reach intoa super heated environment to release a door lock.
In such an instance, a short pike pole or halligan could be used to push the bar out of the way and exert pressure on the panic bar.
Forcible Entry Methods
Figure on this slide shows how a halligan can be used with a sledge hammer to break bolts on the exterior of a steel door to defeat a locking mechanism.
The adze end of the tool is struck with the sledge hammer.
A flat headed axe can also be used to perform a striking function, but it tends to have less weight and may not be as efficient for this purpose.
Forcible Entry Methods
Figure 3–17 shows how a halligan can be used to defeat the hinges on a steel door frame.
Figure 3–18 shows how a halligan can be used to force a door in a steel frame.
Forcible Entry Methods
When using tools like halligans and pike poles, firefighters must be sure to pry down on the tool using body weight to reduce any back strain.
Locating the Fire
•Officer/IC; 360 degree size-up.
•Use thermal imaging camera.
•Assess condition of smoke.
•High ceilings can hide things.
•Watch for signs of flashover.
The first arriving officer should ensure that a 360⁰ exterior reconnaissance is performed as part of the initial size-up. This reconnaissance provides important information that can be used in the decision-making process and formulation of incident action plans.
Thermal imaging cameras and heat guns should be included as part of the on-scene size-up tools to allow companies the opportunity to locate any high heat areas prior to making entry. These tools will not provide accurate readings through glass.
Visible smoke may not provide an accurate indication of the size and advanced state of the fire.
High ceilings with few or no openings to the exterior can mask the level of involvement and the high heat conditions that may be present at the upper levels of the building.
Smoke without any appreciable heat or cold smoke is of grave concern. Although this smoke is cold it still contains volatile fuel elements that can ignite when exposed to a flame source.
Firefighters must constantly look up and analyse the smoke layer to guard against a potential flashover.
Using Master Streams
•Use large master streams to cool structure.
•Direct hose streams through open windows & doors.
•Smooth bore nozzles preferred to deliver large volume of water.
If high heat conditions exist at the roof level of a fire in a Type II building, large diameter hose streams must be directed onto the exposed structural steel to control the heat of the fire and to cool the steel elements before they fail.
Hose streams should be directed from protected windows or doorways to allow rapid egress for fire crews should the building begin to fail.