Ch 19 pg 485-493 danger of partially occupied structures

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What primarily causes spalling in concrete exposed to fire?

Cracking from thermal expansion

Water turning to steam within the concrete (correct)

Chemical reactions within the concrete mix

Inadequate curing of the concrete

Why are lower floors of a building typically unoccupied during construction?

They are usually more costly to rent

They serve as storage areas for construction materials (correct)

Building codes require them to remain empty until completion

They have insufficient access for construction crews

Which of the following statements about sprinkler installation is most accurate?

Sprinklers are installed on lower floors due to higher fire risk

Sprinklers are required on all floors regardless of occupancy

the upper floors being finished and occupied must have operational sprinklers

Install a basic , exposed pipe sprinkler system with 1in outlets for lower floors (correct)

What factor is crucial in reducing the chances of spalling in heated concrete?

Cooling the heated concrete with water Signup and view all the answers

What is a reasonable consideration when installing a sprinkler system in a new building?

Space the heads conservatively to accommodate future changes. Signup and view all the answers

What key factor contributed to the effective design of the sprinkler system in the high-rise building referenced?

Spacing the sprinkler lines every 10 ft to cover 100 sq ft per head. Signup and view all the answers

What is one of the main challenges firefighters face regarding occupied buildings under construction?

Disproportionate life hazards for occupants Signup and view all the answers

Why might the practice of allowing occupancy during construction be seen as acceptable in smaller homes?

They typically have multiple exits for safety Signup and view all the answers

What is a proposed measure to ensure safety when fire protection systems are not fully operational in buildings?

Forbid the use of any floor above the levels with incomplete fire protection Signup and view all the answers

What is one consequence of blocking stairwell doors during construction?

It increases the risk of fire contaminating stairways. Signup and view all the answers

Which factor contributes to the rapid spread of fire in buildings under construction?

Unfinished work that exposes combustible materials Signup and view all the answers

What factor most significantly increases the risk of firefighter fatalities in vacant building fires?

The age and condition of the building Signup and view all the answers

Why do vacant buildings pose a greater danger during firefighting operations compared to occupied buildings?

They often have structural supports removed Signup and view all the answers

What is a critical consideration for firefighters at buildings undergoing demolition?

Assessing the stability of the structure Signup and view all the answers

What must a firefighting crew obtain before entering a building with a box and a x?

Permission from the incident commander Signup and view all the answers

What is the primary advantage of marking vacant buildings with signs rather than spray painting?

It reflects the increased property value in the community. Signup and view all the answers

What is a common vulnerability of the systems used to mark vacant buildings?

Deterioration from exposure to environmental factors Signup and view all the answers

What does a building marked with a box that has one line drawn diagonally through it indicate?

Serious hazards are present, and interior operations should be conducted with caution. Signup and view all the answers

What should be done if a small fire occurs in a building marked with significant hazards?

A careful assessment for hazards should be carried out before interior operations. Signup and view all the answers

Study Notes

Concrete and Fire

Spalling occurs in concrete during exposure to heavy fire, leading to the explosive release of chunks due to trapped water turning into steam.
Heavy spalled chunks can weigh over 100 lbs and typically involve direct flame exposure, reducing risks to firefighters in most scenarios.
Effective cooling of heated concrete requires substantial water, which can be challenging even after flames are extinguished.

Upper vs Lower Floors

The highest floors in buildings are often completed last but rented first due to views and prestige.
Lower floors, frequently used as storage areas for construction materials, present significant fire loads and may lack sprinkler systems.
Construction codes allow unsprinklered lower floors, while the occupied higher floors usually require operational sprinklers for safety.
Conducting firefighting operations in partially occupied buildings is complex due to the mixing of ongoing construction with occupied spaces.

Improving Initial Safety

Implementing temporary sprinkler systems can enhance safety during construction, but if resisted, limiting occupancy to fully protected lower floors is advisable.
Rapid fire spread is common in buildings undergoing renovations, where barriers like doors may be removed, increasing risks to occupants and firefighters.
Safety measures should prevent blockage of stairwell and occupancy doors to reduce potential fire contamination and escape hazards.

Buildings Undergoing Renovation and Demolition

Vacant buildings present the highest risk for firefighter fatalities, with death rates up to five times higher than occupied residential buildings.
Risks in vacant buildings include structural instability and compromised fire protection, necessitating slow, cautious operations.
Markings indicating hazards, such as an "X" for serious risks, signal that operations should predominantly occur outdoors to maintain safety.

Firefighting and Vacant Buildings

Firefighting efforts should prioritize external streams, avoiding entry into occupied structures, especially in unsafe locations.
Situational awareness is essential, as vacant buildings are significant life hazards solely for firefighters present inside.

Marking Vacant Buildings

Different cities, like Alexandria, VA and Nassau County, NY, use visible signage systems to identify vacant buildings, enhancing safety for responders.
Such signs, often vulnerable to environmental and man-made damages, require active monitoring to ensure they remain effective.

The Importance of Caution

Firefighters should not solely rely on building marking systems; comprehensive situational awareness is critical.
Caution is imperative when operating in and around potentially dangerous structures to mitigate risks associated with entering compromised environments.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz explores the effects of fire on concrete, particularly the phenomenon of spalling. Understanding how concrete behaves under high temperatures is crucial for enhancing safety measures for firefighters and preventing structural failures. Dive into the science behind fire exposure and its consequences.