CFI Building Construction & Fire Behavior

Question 1

How does lightweight wood construction affect fire behavior?

Accepted Answer

It fails faster under fire conditions.

Answer

Lightweight wood construction, often found in modern buildings, uses smaller dimensional lumber and engineered wood products. These materials have less mass and surface area compared to traditional heavy timber, making them more susceptible to rapid charring and structural failure when exposed to fire. This significantly reduces the time before collapse, posing increased risks to firefighters and occupants.

Question 2

What is the main concern with concealed spaces in construction during a fire?

Accepted Answer

They allow hidden fire spread.

Answer

Concealed spaces, such as attics, wall cavities, and dropped ceilings, act as hidden pathways for fire and smoke to spread rapidly and undetected throughout a building. This hidden spread makes fire suppression more challenging and increases the risk of extensive damage or structural collapse. Such spaces pose significant hazards by allowing fire to bypass fire-rated barriers.

Question 3

Which building material is most fire-resistant?

Accepted Answer

Concrete

Answer

Concrete is highly fire-resistant due to its non-combustible nature and excellent thermal mass, which allows it to absorb and dissipate heat slowly. Unlike wood, which burns, or steel, which loses strength when heated, concrete maintains its structural integrity for longer periods during a fire. This makes it a preferred material for fire-rated construction and compartmentalization.

Question 4

What role do fire walls play in construction?

Accepted Answer

Separate areas to prevent fire spread.

Answer

Fire walls are specially designed structural barriers constructed to resist the passage of fire for a specified duration. Their primary role is to divide a building into smaller compartments, limiting the spread of fire from one area to another. This provides occupants with more time for evacuation and firefighters with better containment opportunities, enhancing overall building safety.

Question 5

Why is steel vulnerable during a fire?

Accepted Answer

It expands and softens, losing strength.

Answer

While non-combustible, steel is highly susceptible to heat. When exposed to the high temperatures of a fire, steel expands, distorts, and significantly loses its tensile strength and load-bearing capacity. This weakening can lead to rapid structural collapse, making fire protection coatings or encasements crucial for steel-framed buildings to maintain their integrity during a fire.

(CFI) Certified Fire Inspector Practice Test

(CFI) Certified Fire Inspector Practice Test

CFI Building Construction & Fire Behavior