Podcast
Questions and Answers
What is the maximum gap that can be created by the failure of a single bowstring truss?
What is the maximum gap that can be created by the failure of a single bowstring truss?
- 10 ft wide by 60 ft long
- 40 ft wide by 100 or more ft long (correct)
- 15 ft wide by 60 ft long
- 20 ft wide by 40 ft long
What diameter of handlines is considered sufficient for fire operations in exposed stores?
What diameter of handlines is considered sufficient for fire operations in exposed stores?
- 1 1/4 inch
- 2 inch
- 1 3/4 inch (correct)
- 1 inch
What should firefighters do after extinguishing the fire in a store before entering?
What should firefighters do after extinguishing the fire in a store before entering?
- Inspect the store for structural integrity and debris
- Begin ventilating the structure and removing smoke
- Continue to cool the steel joists for several minutes (correct)
- Immediately search for victims in the building
Which action is recommended after stretching handlines into the exposed stores?
Which action is recommended after stretching handlines into the exposed stores?
What consequence might occur if bar joists cool too quickly after a fire?
What consequence might occur if bar joists cool too quickly after a fire?
What is the recommended action to prevent weakening of bar joists during a fire?
What is the recommended action to prevent weakening of bar joists during a fire?
What should be done regarding ventilation while firefighters remain in exposed stores?
What should be done regarding ventilation while firefighters remain in exposed stores?
What distance should firefighters back away from the fire when cutting a bar-joist roof?
What distance should firefighters back away from the fire when cutting a bar-joist roof?
Why is complete evacuation necessary in wood-truss buildings with heavy fire involvement?
Why is complete evacuation necessary in wood-truss buildings with heavy fire involvement?
What is a primary danger associated with lightweight wood-truss roofs during a fire?
What is a primary danger associated with lightweight wood-truss roofs during a fire?
What is a key factor that differentiates commercial fires from residential fires?
What is a key factor that differentiates commercial fires from residential fires?
How does the fire loading per square foot typically compare between commercial and residential properties?
How does the fire loading per square foot typically compare between commercial and residential properties?
Why must engine companies adjust their tactics when responding to commercial fires?
Why must engine companies adjust their tactics when responding to commercial fires?
In terms of fire response priorities, what typically takes precedence in residential occupancy fires?
In terms of fire response priorities, what typically takes precedence in residential occupancy fires?
What water flow rate is estimated as necessary for knockdown in a store measuring 2,000 sq ft?
What water flow rate is estimated as necessary for knockdown in a store measuring 2,000 sq ft?
Which firefighting method is recommended if the deck gun cannot be used due to obstructions?
Which firefighting method is recommended if the deck gun cannot be used due to obstructions?
What approach is suggested for handling a large commercial fire when predicting required fire flows?
What approach is suggested for handling a large commercial fire when predicting required fire flows?
What is the recommended approach for extinguishing fires that have spread to the trusses in a building?
What is the recommended approach for extinguishing fires that have spread to the trusses in a building?
Which firefighting technique is preferred for ensuring coverage of the entire depth of a fire area?
Which firefighting technique is preferred for ensuring coverage of the entire depth of a fire area?
Which type of fire hose line is appropriate for addressing large fires in commercial buildings?
Which type of fire hose line is appropriate for addressing large fires in commercial buildings?
What critical placement consideration should be made when deploying fire hose lines in residential fires?
What critical placement consideration should be made when deploying fire hose lines in residential fires?
Why can lighter, medium-size fire lines be effectively utilized in residential areas?
Why can lighter, medium-size fire lines be effectively utilized in residential areas?
What is the most significant reason for using a 2½-in. hose line during a store fire?
What is the most significant reason for using a 2½-in. hose line during a store fire?
How should the first-arriving engine prepare for a store fire with heavy smoke visible?
How should the first-arriving engine prepare for a store fire with heavy smoke visible?
What is a potential risk when positioning the engine too close to a store fire?
What is a potential risk when positioning the engine too close to a store fire?
What benefit does using one or two large-diameter hose provide compared to a direct hydrant connection?
What benefit does using one or two large-diameter hose provide compared to a direct hydrant connection?
Which strategy is recommended when a fire is not blowing out windows upon arrival?
Which strategy is recommended when a fire is not blowing out windows upon arrival?
What is the expected effectiveness of a 2½-in. line in terms of personnel operation?
What is the expected effectiveness of a 2½-in. line in terms of personnel operation?
In which scenario is a preconnected master stream most effectively utilized?
In which scenario is a preconnected master stream most effectively utilized?
How does the reach of a 2½-in. hose line contribute to firefighting in stores?
How does the reach of a 2½-in. hose line contribute to firefighting in stores?
What is the advantage of using the 1 ¼-in. solid tip nozzle with a flow rate of 325 gpm?
What is the advantage of using the 1 ¼-in. solid tip nozzle with a flow rate of 325 gpm?
When maneuvering with three members in a commercial store setting, what is the initial action recommended?
When maneuvering with three members in a commercial store setting, what is the initial action recommended?
In a situation requiring two lines of medium-size hose, how many firefighters are needed at a minimum?
In a situation requiring two lines of medium-size hose, how many firefighters are needed at a minimum?
What factor makes the layout of a strip-mall store different from that of a residence during firefighting?
What factor makes the layout of a strip-mall store different from that of a residence during firefighting?
Flashcards
What are bar joists?
What are bar joists?
Used for structural support in roofs, they are spaced 2 to 6 feet apart and can extend up to 60 feet in length.
What is the potential impact of bar joist failure?
What is the potential impact of bar joist failure?
If two or three bar joists fail, it can result in a collapse spanning 10-15 ft wide and 60 ft long.
Why is protecting steel bar joists from heat important?
Why is protecting steel bar joists from heat important?
It's crucial to prevent steel bar joists from getting too hot because they lose strength when heated. Applying water cools them down, reducing the risk of failure.
What firefighting equipment is recommended for reaching and cooling steel bar joists?
What firefighting equipment is recommended for reaching and cooling steel bar joists?
Signup and view all the flashcards
What can happen to steel bar joists during cooling?
What can happen to steel bar joists during cooling?
Signup and view all the flashcards
What strategy should be employed during strip mall fire operations to protect joists?
What strategy should be employed during strip mall fire operations to protect joists?
Signup and view all the flashcards
What precautions should be taken when cutting roofs during strip mall fires?
What precautions should be taken when cutting roofs during strip mall fires?
Signup and view all the flashcards
What are the challenges and considerations regarding ventilation in strip malls?
What are the challenges and considerations regarding ventilation in strip malls?
Signup and view all the flashcards
Why is full evacuation necessary in the case of heavy fire involving wood trusses?
Why is full evacuation necessary in the case of heavy fire involving wood trusses?
Signup and view all the flashcards
What dangers are associated with interior firefighting in buildings with wood trusses?
What dangers are associated with interior firefighting in buildings with wood trusses?
Signup and view all the flashcards
What strategy should be employed for firefighting in high-risk conditions involving wood trusses?
What strategy should be employed for firefighting in high-risk conditions involving wood trusses?
Signup and view all the flashcards
What type of hose lines are recommended for commercial structure fires?
What type of hose lines are recommended for commercial structure fires?
Signup and view all the flashcards
What preparations should be made for commercial fire response regarding hose lines?
What preparations should be made for commercial fire response regarding hose lines?
Signup and view all the flashcards
What tactics should be used during the initial attack on commercial fires?
What tactics should be used during the initial attack on commercial fires?
Signup and view all the flashcards
What are the advantages of using larger hose lines (2 ½ in.) for fire suppression?
What are the advantages of using larger hose lines (2 ½ in.) for fire suppression?
Signup and view all the flashcards
How do larger hose lines affect crew performance and safety?
How do larger hose lines affect crew performance and safety?
Signup and view all the flashcards
What are the advantages of strip mall layouts for fire suppression?
What are the advantages of strip mall layouts for fire suppression?
Signup and view all the flashcards
What are potential fire hazards associated with cockloft areas in strip malls?
What are potential fire hazards associated with cockloft areas in strip malls?
Signup and view all the flashcards
What is the estimated water flow rate required for commercial fire suppression?
What is the estimated water flow rate required for commercial fire suppression?
Signup and view all the flashcards
What are the water flow requirements for larger stores and why are special equipment like deck guns needed?
What are the water flow requirements for larger stores and why are special equipment like deck guns needed?
Signup and view all the flashcards
Study Notes
Bar-Joist Roofs and Firefighting Tactics
- Bar joists are spaced 2 to 6 ft apart; wooden bowstring trusses typically span 20 ft.
- Bar joists can extend up to 60 ft in length; hard to determine their orientation from outside.
- Failure of two to three bar joists can collapse an area 10-15 ft wide and 60 ft long; a single bowstring truss can cause a gap of 40 ft by 100 ft.
- Protecting steel bar joists from heat is crucial; applying water streams can prevent failure.
- Initiate fire attack from safe positions using a 2 1/2 in. handline or master stream for effective reach and cooling of the steel.
- Monitor for steel contraction as it cools, which can detach joists from their supports.
Firefighting Operations in Strip Malls
- Coordination among hose streams and roof ventilation is essential to prevent weakening joists.
- Avoid cutting directly over fire locations; reposition at least three stores away from sagging joists.
- Thorough ventilation is necessary as rear and side areas are often sealed; roof venting may be required.
Wood Truss Roofs Risks
- Lightweight wood trusses fail rapidly, necessitating full evacuation if heavy fire is present.
- Historical incidents highlight the dangers of interior firefighting involving wood trusses, leading to fatal outcomes.
Firefighting Equipment and Techniques
- Use exterior streams to remove ceilings and suppress fire during high-risk conditions.
- Fire attack requires large hose lines (2 ½ in.) for commercial buildings due to increased fire load and space.
Preparing for Commercial Fire Response
- Expect prolonged engagement and connect to hydrants with large-diameter hoses (5 or 6 in.) for flexibility and increased water delivery.
- Initial fire attacks should utilize deck guns or master streams for immediate suppression when fires are visible.
Advantages of Larger Hose Lines
- A 2 ½ in. hose delivers 250-325 gpm and has a reach over 80 ft, vital for immediate fire suppression.
- Crew performance is enhanced as fewer members manage the larger line while advancing towards the fire.
Maneuverability in Strip Malls
- The layout of strip mall stores allows for efficient hose deployment and straightforward advancement.
- Maintain awareness of potential overhead cockloft fires; may require creating access holes for effective water application.
Water Flow Requirements
- Expect commercial fires to require approximately 0.35 gpm per square foot for suppression.
- A 2,000 sq ft store may necessitate around 700 gpm, often exceeding the capacity of single large-tipped hoses, making deck guns or portable master streams essential.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Explore the intricacies of structural failures in store fires, focusing on bar joists and their impact in taxpayers and strip malls. This quiz delves into how spacing and failure patterns influence fire safety and building integrity. Test your knowledge on these critical aspects of fire risk management.
