The Art of Reading Buildings Quiz Chapters 2

Questions and Answers

What has happened to the number of skilled building tradespeople within the fire service?

Their numbers are dwindling quickly. (correct)

They have increased significantly over the years.

They are being replaced by technology.

Their numbers have remained the same.

What is primarily responsible for creating most loads on a building?

Natural phenomena such as earthquakes.

Gravity acting on the structure and its contents. (correct)

Human-made objects placed within the building.

Atmospheric conditions like wind and rain.

Which of the following terms is NOT mentioned as having little meaning to new recruits?

Rafter tie plate

Ledger

Moisture resistance (correct)

Torsion

What type of loads are defined as static weights that come from the building and anything that acts upon it?

Dead loads Signup and view all the answers

What is one of the essential characteristics that new recruits possess, despite lacking building trade knowledge?

Capacity to learn and absorb information. Signup and view all the answers

What is a potential consequence of firefighters lacking knowledge in building construction?

Increased danger during fire suppression operations. Signup and view all the answers

Which atmospheric condition is mentioned as contributing to loads on a building?

Snowfall Signup and view all the answers

Which of the following skills do the new recruits excel in, even though they may lack practical construction experience?

Familiarity with phone apps. Signup and view all the answers

What characterizes a concentrated load?

A load applied within a small area or at one point. Signup and view all the answers

What type of load is a firefighter's team when operating on a roof considered to be?

Live, impact, and distributed load. Signup and view all the answers

Which of the following is NOT a way loads can be imposed on materials?

Bending load. Signup and view all the answers

Which describes the type of stress caused by a material being pulled apart?

Tensile stress. Signup and view all the answers

What factor is NOT considered when evaluating material characteristics for load resistance?

Acoustic properties. Signup and view all the answers

What type of load is typically experienced during high winds or heavy snowfall?

Wind/snow load. Signup and view all the answers

Which of the following loads is characterized as being transient or intermittent?

Repeated load. Signup and view all the answers

What characteristic allows materials to absorb heat effectively under fire conditions?

Mass relative to surface area. Signup and view all the answers

In the context of loads, what do forces primarily help to do?

Resist the imposed loads. Signup and view all the answers

What is the term for the total heat energy potential that may be released during combustion in materials?

Fire load. Signup and view all the answers

Which stress type results from the twisting of a material?

Torsion. Signup and view all the answers

What type of load would a large crowd imposing weight on a structure be classified as?

Live load. Signup and view all the answers

Which scenario exemplifies an eccentric load application?

A person standing at the edge of a beam. Signup and view all the answers

How is the process of load imposition primarily described?

The orientation of the load application to the material. Signup and view all the answers

What characterizes a ductile material in comparison to a brittle material?

It bends before it breaks. Signup and view all the answers

Which of the following statements is true regarding the surface-to-mass ratio of building materials?

A high surface-to-mass ratio indicates low heat resistance. Signup and view all the answers

In modern building materials, what has been a significant change regarding wood?

Engineered wood products are increasingly replacing native wood. Signup and view all the answers

What does the current lumber industry's change in rating from Utility to #3, #2, and #1 indicate?

A decline in the quality of wood being used for structural members. Signup and view all the answers

How does hewing techniques differ between old-growth and new-growth trees?

Old-growth trees were cut primarily for density and minimal pitch. Signup and view all the answers

Which of the following correctly identifies a disadvantage of new lightweight construction methods?

They may lead to quicker wood burn rates. Signup and view all the answers

What is a key factor to consider when evaluating material performance in a fire from a firefighter's perspective?

The surface-to-mass ratio of the materials. Signup and view all the answers

Which type of wood is highlighted as commonly used for exterior load-bearing walls in modern construction?

Douglas fir for high strength. Signup and view all the answers

What distinguishes nominal dimension lumber from full-dimensional lumber?

Nominal dimension lumber measures less than the labeled dimensions. Signup and view all the answers

Which property is commonly attributed to masonry and tile as building materials?

They exhibit brittleness and can fracture under stress. Signup and view all the answers

What impact does a higher concentration of pitch in new-growth wood have?

It increases the speed at which the wood burns. Signup and view all the answers

Which material is considered a composite of traditional building materials?

Engineered wood products. Signup and view all the answers

Why is mass critically regarded in the context of fire safety in modern buildings?

It provides a heat resistance buffer for structural integrity. Signup and view all the answers

What fundamental change affects the composition of wood used in modern construction compared to traditional methods?

Today's wood is often derived from smaller and younger trees. Signup and view all the answers

What is the primary advantage of engineered wood products over solid wood?

Greater strength and stiffness per unit weight Signup and view all the answers

Which type of adhesive is the most common in engineered wood products?

Urea-formaldehyde Signup and view all the answers

What characteristic of glued laminated timber (GLT) makes it appealing to designers?

Ability to be produced in curved shapes Signup and view all the answers

What is a significant disadvantage of using oriented strand board (OSB) in fire situations?

It is highly susceptible to heat degradation Signup and view all the answers

What flaw in engineered wood products can lead to faster burning rates compared to solid wood?

High surface-to-mass ratio Signup and view all the answers

What is a notable fire service concern related to the adhesives used in engineered wood products?

Some are toxic and emit harmful gases Signup and view all the answers

Which type of steel construction has excellent strength due to its specific manufacturing process?

Hot-rolled steel Signup and view all the answers

Which material is noted for having a strength-to-weight ratio superior to that of steel?

Engineered wood products Signup and view all the answers

What characteristic does steel lose when subjected to elevated temperatures?

Tensile strength Signup and view all the answers

What is the primary use of finger-jointed lumber (FJL) in construction?

Joining short pieces of lumber Signup and view all the answers

What is one reason engineered wood products may not be optimal for fire service considerations?

They often utilize harmful resins in fabrication Signup and view all the answers

Which attribute of steel allows for significant versatility during manufacturing?

Ductility and fabrication options Signup and view all the answers

What is the material most commonly used for producing engineered wood products?

Rapid-growth timber Signup and view all the answers

What is a primary reason why engineered wood products are replacing traditional materials in construction?

More favorable environmental impact Signup and view all the answers

At what temperature does cold-drawn steel typically lose 55% of its strength?

800 °F Signup and view all the answers

What is a major characteristic of cast iron compared to steel?

It is a brittle material. Signup and view all the answers

Why is aluminum rarely used for the main structure of buildings?

It is too expensive. Signup and view all the answers

What happens to structural steel when it is heated to 1,100 °F?

It loses 50% of its strength. Signup and view all the answers

What is the effect of applying cold water to fire-heated cast iron?

It can lead to explosive fracturing. Signup and view all the answers

What is a primary reason for the debate over fire suppression methods on cast iron?

It can fracture due to impact loads. Signup and view all the answers

How does structural steel behave at temperatures above 800 °F?

It elongates and may twist or buckle. Signup and view all the answers

What is one reason titanium is not widely used in construction despite its properties?

The cost of production is prohibitively high. Signup and view all the answers

What primary property makes aluminum suitable for applications like trim and brackets?

Resistance to corrosion. Signup and view all the answers

In a fire, the low mass of aluminum can lead to what?

Rapid structural failure. Signup and view all the answers

How does the elongation of steel affect a beam fixed at both ends when heated?

It can lead to twisting or buckling. Signup and view all the answers

Why was cast iron used extensively in structural applications in the 1800s?

It allowed for intricate designs. Signup and view all the answers

Which metal is known for its excellent strength-to-weight ratio and resistance to heat?

Titanium Signup and view all the answers

Which of the following characteristic is TRUE for cast iron?

It tends to fracture under stress or heat. Signup and view all the answers

What is a critical difference between traditional wood products and engineered wood products?

Engineered wood products utilize technological advancements for construction. Signup and view all the answers

Why do lightweight wood constructions fail more rapidly during fires compared to traditional lumber?

They lack clear warning signs like sagging before collapse. Signup and view all the answers

What is the primary purpose of plywood in construction?

To serve as a high surface-to-mass covering material. Signup and view all the answers

How do the adhesives in glazed laminated beams respond to fire conditions?

They can emit toxic gases when burned. Signup and view all the answers

What kind of fires do glulam beams typically withstand before failing?

Heavy or lengthy fire conditions. Signup and view all the answers

Which feature characterizes particle board in terms of strength?

It has low resistance to trauma and can crumble easily. Signup and view all the answers

What property of decorative sheathing limits its use in interior wall finishes?

It has a high surface-to-mass ratio and rapid flame spread. Signup and view all the answers

Why is plywood considered the original engineered wood product?

It is made by layering sheet veneers with alternating grain directions. Signup and view all the answers

Which factor contributes to the intense burning characteristics of lightweight wood construction?

It has less mass compared to traditional lumber. Signup and view all the answers

What material is primarily used in traditional wood sheathing products?

Wood by-products like plywood and particle board. Signup and view all the answers

What happens to plywood when exposed to serious heat?

It starts to warp and may lose adhesion between layers. Signup and view all the answers

What characteristic of construction using glulam beams makes it popular today?

They have the ability to absorb significant heat before failing. Signup and view all the answers

How does pressure treatment affect wood products in construction?

It enhances resistance to pests but may weaken the structure over time. Signup and view all the answers

Which wood product is most likely to emit toxic smoke when burned?

Glued laminated beams. Signup and view all the answers

What characteristic of engineered wood products generally contributes to their lightweight nature?

Loose grain structure Signup and view all the answers

Which engineered wood product is formed by stacking thin veneers with aligned grains?

Laminated veneer lumber Signup and view all the answers

What is a major factor that contributes to the fire degradation of OSB?

The adhesives used Signup and view all the answers

Which product is NOT typically classified as an engineered wood product?

Plywood Signup and view all the answers

Why is cross-laminated timber gaining acceptance in construction?

It offers better acoustics than traditional materials Signup and view all the answers

What is the main composition of laminated strand lumber?

Flaked and chipped strands of native wood Signup and view all the answers

What is a common use for laminated veneer lumber (LVL)?

Structural beams and columns Signup and view all the answers

What weakens laminated veneer lumber during a fire?

Delamination caused by heat Signup and view all the answers

How does the composition of engineered wood products impact their behavior in fire conditions?

They burn rapidly and emit toxic gases from adhesives Signup and view all the answers

What type of adhesive is commonly used in oriented strand board?

Urea-formaldehyde Signup and view all the answers

What is a disadvantage of using lightweight wood trusses compared to older lumber?

They do not sag before a catastrophic collapse Signup and view all the answers

Which type of wood product is derived from wood chips and shavings combined with gluing agents?

Laminated strand lumber Signup and view all the answers

What is a notable strength of engineered wood products compared to natural wood?

Increased resistance to twisting and warping Signup and view all the answers

Which of the following engineered wood products typically has a higher mass than OSB?

Laminated veneer lumber Signup and view all the answers

What is the primary role of steel reinforcement in concrete?

To enhance tensile strength Signup and view all the answers

Which component is NOT typically a part of concrete's composition?

Steel fibers Signup and view all the answers

What causes spalling in concrete during a fire?

Moisture vaporization within the concrete Signup and view all the answers

What characteristic of concrete makes it particularly vulnerable after exposure to fire?

Brittleness Signup and view all the answers

How does the compressive strength of masonry change under axial loads?

It increases Signup and view all the answers

What is a primary disadvantage of mortar in masonry construction?

It can deteriorate over time Signup and view all the answers

What is a defining property of thermosetting plastics?

They remain permanently solid once set Signup and view all the answers

What happens to the heat and moisture content in concrete during a fire event?

It is absorbed, leading to expansion and cracking Signup and view all the answers

Which characteristic does NOT describe monolithic construction?

It involves complex assembly of separate units Signup and view all the answers

What type of loads must be avoided to maintain the integrity of a masonry wall?

Eccentric loads Signup and view all the answers

Which of the following materials is NOT typically found in masonry construction?

Fiberboard Signup and view all the answers

Which factor directly impacts the final strength of concrete?

The type of aggregate used Signup and view all the answers

What is the significance of the water-to-cement ratio in concrete?

It influences the brittleness of the final product Signup and view all the answers

What makes composites potentially dangerous in firefighting contexts?

Their maximum strength at minimal mass Signup and view all the answers

What is a significant disadvantage of using thermosetting plastics in construction?

They break down upon reheating. Signup and view all the answers

How do carbon-fiber reinforced polymers (CFRPs) primarily benefit construction materials?

They offer high tensile strength and are corrosion resistant. Signup and view all the answers

What impact does the melting of plastics in a fire have on building stability?

It can lead to increased instability as plastics emit explosive gases. Signup and view all the answers

What is a key characteristic of concrete that limits its application in construction compared to other materials?

Poor tensile and shear strength. Signup and view all the answers

Which composite is often reinforced with steel to enhance its building properties?

Reinforced concrete Signup and view all the answers

What is a common application of CFPRs despite their cost?

To reinforce concrete and steel structures. Signup and view all the answers

How does the surface-to-mass ratio of building materials influence fire degradation?

Higher ratios lead to increased heat release rates. Signup and view all the answers

What is one effect of spalling on masonry during a fire?

It weakens the masonry and can cause instability. Signup and view all the answers

What is one reason why the building industry would increasingly adopt plastics as materials?

Their lightweight properties can ease construction challenges. Signup and view all the answers

What two conditions during a fire can cause a masonry wall to become unstable?

Spalling and loss of structural integrity. Signup and view all the answers

What is the primary purpose of adding steel reinforcement to concrete?

To enhance its tensile and shear strength. Signup and view all the answers

How is the trend of using composites in construction affecting firefighters?

It requires them to adapt to new fire behavior and stability risks. Signup and view all the answers

At what point does hot-rolled (extruded) steel begin to lose its structural integrity?

At around 650°F. Signup and view all the answers

What is a primary reason plastic materials are not widely used for load-bearing structures?

Their melting point is significantly lower than other materials. Signup and view all the answers

Study Notes

Fire Service and Building Trade Knowledge

Many firefighters have backgrounds in building trades such as carpentry, plumbing, and electrical work, either as volunteers or part-timers.
A decline has been observed in new recruits having building trade backgrounds, necessitating additional training in building construction fundamentals.
Core building concepts like loads and material strengths are essential for understanding potential building failures during fire suppression.

Understanding Loads in Building Structures

A building must be able to withstand various loads, which are static and dynamic forces stemming from the structure and external factors.
Major types of loads include:
- Dead loads: The weight of the structure and any permanently attached components.
- Live loads: Any transient or movable weights (e.g., furniture, people).
- Additional classifications: concentrated loads, distributed loads, impact loads, repeated loads, static loads, suspended loads, and wind/snow loads.
The term fire load refers to the potential heat energy from burning materials measured in British thermal units (BTUs).

Load Imposition and Interaction with Materials

Loads can be imposed through three mechanisms:
- Axial load: Applied through the center of a material.
- Eccentric load: Applied off-center, inducing bending.
- Torsion load: Causes twisting in the material.
Imposed loads create stresses in materials termed as:
- Compression: Material is flattened or crushed.
- Tension: Material is stretched apart.
- Shear: Material is torn or slides apart.

Material Characteristics and Their Role in Construction

Material suitability for construction depends on various factors, including type, shape, orientation, mass, and surface properties.
Surface-to-mass ratio is critical for firefighters; higher mass relative to surface area enhances heat resistance.
As materials burn, loss of mass impacts structural integrity, with emphasis on how fire affects resistance to loads.

Evolution of Building Materials

Traditional materials include wood, steel, concrete, and masonry, but innovative materials and composites are increasingly utilized.
A shift from older, denser, and lower-pitch wood to lighter, faster-burning new-growth trees is evident.
Modern lumber is generally lighter and less dense, causing faster and hotter burn rates than historical equivalents.

Engineered and Traditional Wood Products

Engineered wood products may replace traditional hardwoods, leading to structural changes that impact fire resistance.
Glued laminated timber (glulam) is used to create stronger beams from smaller pieces, maintaining strength under heat but presenting risks if adhesives fail during fire.
Common sheathing materials include:
- Plywood: Made of alternating layers of wood veneer, vulnerable to fire.
- Particle board: Low resistance to fire, prone to breaking under pressure.
- Decorative sheathing: Typically not load-bearing, contributing to rapid flame spread and toxicity when burnt.

Safety Implications for Firefighters

Understanding building materials and their behaviour under heat is crucial for firefighting and rescue operations, as modern lightweight constructions can fail suddenly without prior warning signs.
Traditional wood structures provided visual cues (e.g., sagging) for failure signs, which may not be present in contemporary lightweight materials.### Engineered Wood Products (EWP)
Older roofs with conventional materials can sag before collapsing; newer lightweight wood trusses do not show such signs prior to failure.
Traditional wood products include sawn lumber items like glue-laminated (glulam) timber and plywood sheathing.
Plywood and similar products can emit flammable, toxic gases when exposed to heat or fire.
Engineered wood utilizes weight-efficient materials made from wood chips, veneers, and recycled products, replacing sawn lumber and sheathing.
EWP is sourced from new-growth forests or rapid-growth tree farms and can include non-wood fibers like hemp and wheat straw.
The production process involves milling wood into finer forms, emulsifying in adhesives, and autoclaving to set the bindings.
Common engineered wood types include Oriented Strand Board (OSB), Laminated Veneer Lumber (LVL), Laminated Strand Lumber (LSL), Cross-Laminated Timber (CLT), and Glued Laminated Timber (GLT).

Types of Engineered Wood

OSB: Structural sheathing formed with wood shavings and urea-formaldehyde adhesive, aligned to achieve multidirectional strength; degrades rapidly with heat and direct flame.
LVL: Made from thin wood veneers glued with phenolic resin, designed for structural beams and commonly used as replacement for solid lumber.
LSL: Consists of flaked wood strands glued together; used similarly to LVL but may fail faster under fire conditions.
CLT: Panels of timber boarded crosswise, used for structural columns and walls; offers better acoustics and reduced carbon footprint compared to traditional lumber.
GLT: Comprised of multiple layers of dimensional timber for structural elements, it can be shaped to fit aesthetic design needs.

Fire Service Considerations

Engineered wood presents advantages like increased strength and efficient material use but poses fire risks due to flammability and toxic gas emissions.
Adhesives in engineered wood, such as urea-formaldehyde, phenolic, and melamine-formaldehyde, release harmful gases when heated.

Steel as a Building Material

Steel is vital for large commercial structures due to its high strength, versatility, and ability to be fabricated into various shapes and sizes.
Manufactured from iron ore and carbon, the processes include casting, hot-rolling, and cold-rolling.
Steel loses significant strength at elevated temperatures, with a notable reduction at 800°F and 1,100°F which can lead to structural failure due to elongation and buckling.

Cast Iron Characteristics

Known for good compressive strength but is brittle; susceptible to cracking under load, especially in high-temperature environments.
Cast iron resists slow heating but can fracture due to sudden temperature changes or impact from firefighting efforts.

Aluminum and Titanium

Aluminum: Soft metal with a great strength-to-weight ratio, used primarily for trims and special applications; fails quickly in fires.
Titanium: Lightweight and corrosion-resistant with excellent heat resistance, rarely used in construction due to high costs but may become more prevalent in innovative designs.

Concrete Properties

Concrete is a composite material comprising Portland cement, sand, gravel, and water, known for its excellent compressive strength but poor tensile strength.
Curing leads to a solid mass, with the final strength being dependent on the water-to-cement ratio.
Common forms include reinforced concrete (with steel rebar) and precast slabs.
Concrete acts as a heat sink and tends to crack or spall when moisture content expands during heating.### Concrete and Spalling
Spalling weakens concrete by reducing its critical mass, crucial for structural integrity.
Exposed steel rebar can conduct heat from a fire, leading to further spalling and potential failure.
Concrete retains heat after a fire, posing risks to firefighters during overhaul.

Masonry Materials and Construction

Masonry includes materials like brick, tile, concrete block (CMU), and stone, known for their brittleness.
CMU, commonly used for walls, offers compressive strength, suitable for load-bearing and veneer structures.
Mortar, made from sand, cement or lime, and water, binds masonry units but has minimal tensile or shear strength.

Structural Responses

Masonry walls strengthen under axial loads but have a maximum weight limit before failure occurs.
Despite excellent fire resistance, walls may collapse post-fire without roof support due to lack of compressive forces.
Mortar's susceptibility to spalling, aging, and washout can compromise wall stability during fires.

Composite Materials

Composites combine various materials, including plastics and metals, designed for strength with minimal mass, challenging for firefighting.
Plastics, derived from petroleum, are prevalent in construction for their versatility, but they melt readily and emit hazardous gases when burning.

Carbon-Fiber Reinforced Polymer (CFRP)

CFRPs consist of carbon fibers bound by polymers, providing high strength and resistance to heat and corrosion.
CFRPs maintain heat resistance initially but can deteriorate under fire, releasing harmful carbon particles.

Evolving Building Technologies

Advances in material science are leading to increased use of composites, raising concerns for fireground operations.
Staying informed about new technologies in building materials is essential for firefighters to modify their operational tactics.

General Building Concepts

Concrete combines sand, aggregate, water, and Portland cement, prized for its compressive strength but weak in tension and shear.
Reinforcement with steel enhances concrete's performance in tensile applications; forms include monolithic, pre-tensioned, and precast.
Technological advancements continuously influence building construction materials and methods.

Key Questions for Review

Understand the types of loads and their effects on materials.
Differentiate between compression, tension, and shear forces.
Recognize factors influencing suitable materials in construction.
Distinguish between brittle and ductile materials.

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Description

Test your knowledge on the essential aspects of building construction relevant to the fire service. This quiz covers the understanding of loads, the number of skilled tradespeople, and the significance of construction knowledge for new recruits. Assess your grasp of key terms and concepts crucial for effective firefighting.