Metals and Glass in Interior Environments

Introduction and Context

Metals and glass are essential materials in contemporary interior environments. Metals provide structural capacity, durability, thin profiles, reflectivity, colour, and precision detailing. Glass provides transparency, daylight transmission, visual continuity, acoustic separation, and opportunities for display and enclosure. Their successful use depends not only on appearance but also on material science, fabrication, corrosion behaviour, safety, optical performance, maintenance, and regulatory compliance.

Interior designers and managers must therefore select materials through a performance-based process. A visually attractive finish may be unsuitable if it corrodes in a humid environment, creates glare, breaks dangerously, stains adjacent materials, or cannot be fabricated within the project budget. This chapter examines ferrous and non-ferrous metals, alloys, surface treatments, architectural glass, fabrication methods, detailing principles, and the principal safety and code considerations governing their use.

Learning Objectives

By the end of this chapter, the learner should be able to:

1. Distinguish ferrous metals, non-ferrous metals, and common architectural alloys.
2. Select metals according to strength, weight, corrosion resistance, appearance, fabrication, and cost.
3. Explain the purpose and limitations of coatings, plating, anodising, and patination.
4. Classify architectural glass by manufacture, treatment, performance, and application.
5. Specify glass according to safety, thermal, acoustic, optical, and privacy requirements.
6. Develop appropriate joints, supports, tolerances, and interfaces between metals and glass.
7. Identify relevant risks, quality-control procedures, sustainability issues, and code requirements.

1. Metals: Structure, Classification and Selection

A metal is a material whose atoms are arranged in a metallic structure, allowing relatively high electrical and thermal conductivity, ductility, and the reflection of light. Engineering performance is influenced by composition, grain structure, heat treatment, forming process, and surface condition.

1.1 Ferrous and non-ferrous metals

Ferrous metals contain iron as their principal constituent. Mild steel, carbon steel, cast iron, and stainless steel are the principal ferrous materials used in interiors. Steel offers high strength and stiffness at relatively low cost, but unprotected carbon steel readily oxidises in the presence of water and oxygen.

Non-ferrous metals contain little or no iron. Aluminium, copper, brass, bronze, zinc, and titanium are common examples. They are generally selected for low density, corrosion resistance, colour, conductivity, or distinctive surface character.

1.2 Alloys and material grades

An alloy is a metallic material modified by adding one or more elements. Alloying can improve strength, hardness, corrosion resistance, castability, weldability, or appearance. The designation of a grade must be treated as a performance specification rather than a decorative label.

Carbon steel contains iron and carbon, with other elements in controlled quantities. Low-carbon steel is relatively easy to form and weld. Stainless steel contains sufficient chromium to form a thin passive oxide film. This film reforms when damaged, provided oxygen is available and the surface is not contaminated. Common austenitic stainless steels include grades comparable to 304 and 316; the latter generally performs better in chloride-rich or coastal environments because of its molybdenum content. Exact suitability must be confirmed against the governing standard and environmental exposure.

Aluminium alloys are valued because aluminium has a low density and forms a protective oxide layer. Different alloy families provide different combinations of formability, strength, and resistance to marine exposure. Copper alloys include brass, principally copper-zinc, and bronze, a broader family traditionally associated with copper-tin compositions. Their colour changes naturally through oxidation and handling.

Material selection should identify the standard, grade, temper, thickness, finish, and required test evidence. The vague specification “metal finish” is inadequate for procurement and quality control.

2. Engineering and Environmental Criteria

2.1 Strength, stiffness and weight

Strength is resistance to failure under load; stiffness is resistance to deformation. These are not interchangeable. A thin aluminium panel may have adequate strength but deflect more than a steel panel of the same geometry because its elastic modulus is lower. Deflection, vibration, connection strength, and impact resistance must be considered in addition to ultimate strength.

For a uniform axial member, normal stress is expressed as:

where σ is average normal stress in pascals (Pa), F is axial force in newtons (N), and A is cross-sectional area in square metres (m²). This relationship assumes a simple, centrally loaded member with a reasonably uniform stress distribution. It does not by itself verify buckling, local instability, connection failure, or code compliance.

For a simply supported beam carrying a uniformly distributed load, the maximum bending moment is:

where M_max is maximum moment, w is load per unit length, and L is span. This is a specific idealisation: simple supports, a prismatic beam, small deflection, and a uniformly distributed load. Interior designers should normally obtain structural verification from a qualified engineer.

Density affects handling and dead load. The mass of a component can be estimated by:

where m is mass in kilograms, ρ is density in kilograms per cubic metre, and V is volume in cubic metres. The equation is valid when density is reasonably uniform and does not include packaging, fixings, or coatings unless their volumes are added.

2.2 Corrosion and galvanic action

Corrosion is the deterioration of a material through chemical or electrochemical reaction with its environment. Moisture, salts, acids, pollutants, temperature, oxygen availability, and contact with dissimilar metals influence the rate.

Carbon steel commonly develops iron oxide. Stainless steel and aluminium rely on passive oxide films. Copper and bronze often develop a patina that may be protective but may also stain porous stone or grout. Corrosion is accelerated where water is trapped, drainage is absent, protective coatings are damaged, or contaminants remain on the surface.

Galvanic corrosion occurs when dissimilar metals are electrically connected in the presence of an electrolyte such as water. The less noble metal becomes the anode and corrodes preferentially. Risk is reduced by separating metals with compatible washers, gaskets, paints, sealants, or isolating tapes; preventing water retention; and selecting suitable material combinations. Fasteners require particular attention because a small anodic component connected to a large cathodic surface may deteriorate rapidly.

2.3 Fire, heat and hygiene

Metal is non-combustible in ordinary interior applications, but it conducts heat and can lose strength at elevated temperature. Aluminium melts at a lower temperature than steel, and thin decorative components may deform during a fire. Adhesives, laminates, powder coatings, and plastic interlayers can introduce combustible content.

In healthcare, food-service, and laboratory interiors, smooth, cleanable, non-porous surfaces and hygienic joints are important. Stainless steel is widely used, but even stainless steel can stain or pit if cleaned with chlorides, contaminated by carbon-steel tools, or exposed to unsuitable chemicals.

3. Metal Fabrication and Surface Treatment

3.1 Fabrication processes

Common processes include cutting, shearing, punching, drilling, bending, rolling, stamping, casting, extrusion, machining, welding, brazing, and mechanical fastening.

Extrusion is especially significant for aluminium because complex constant cross-sections can be produced efficiently. It supports modular trims, frames, channels, and mullions. Stainless steel and carbon steel are commonly supplied as sheet, plate, tube, bar, or rolled sections. Laser cutting provides accurate profiles but may create heat-affected zones and sharp edges. Welded assemblies require control of distortion, weld appearance, cleaning, and, for stainless steel, removal of heat tint where corrosion resistance is required.

Designers must allow for material thickness, bend radii, weld access, joint movement, tooling limitations, and realistic tolerances. A folded metal panel that appears simple in elevation may require corner reliefs, returns, stiffeners, and concealed fixing zones.

3.2 Finishes and coatings

Surface treatments serve decorative, protective, or functional purposes.

• Painting: Liquid or powder coatings provide colour and barrier protection. Surface preparation, primer compatibility, film thickness, edge coverage, and curing are critical.
• Powder coating: Electrostatic powder is cured thermally. It provides a consistent finish but can be difficult to repair invisibly and may be unsuitable for some heat-sensitive substrates.
• Anodising: Aluminium is electrochemically treated to thicken its oxide layer. It provides durable colour and corrosion resistance, but colour matching between batches can be difficult.
• Electroplating: A thin layer of one metal is deposited on another. Chrome, nickel, zinc, and precious-metal finishes may be used for wear, appearance, or corrosion protection. Poor preparation can cause blistering or peeling.
• Polishing and brushing: These create directional or reflective finishes but may reveal scratches and fingerprints.
• Patination: Chemical or natural oxidation develops a controlled surface colour, particularly on copper and bronze. Samples and maintenance instructions are essential.
• Hot-dip galvanising: Steel is coated with zinc for substantial corrosion protection, especially in exposed or service areas. The appearance is industrial and dimensional tolerances must be considered.

A finish schedule should state substrate, preparation, coating system, colour reference, gloss or texture, exposed faces, edge treatment, repair method, and acceptance sample.

4. Architectural Glass

Glass is an amorphous, inorganic material formed primarily from silica with modifying and stabilising ingredients. Unlike crystalline materials, it does not have a regular long-range atomic lattice. It is rigid and transparent, but it is brittle and sensitive to flaws, edge damage, thermal gradients, and concentrated impact.

4.1 Basic glass types

Float glass is the standard flat glass manufactured by floating molten glass on a bath of molten tin. It has smooth, parallel surfaces and is available in clear, tinted, patterned, coated, and laminated forms. Ordinary annealed float glass is not safety glass where human impact is foreseeable.

Patterned or figured glass has a textured surface produced during manufacture. It diffuses light and reduces direct visibility but may be more difficult to clean and may have directional appearance.

Low-iron glass reduces the green tint found in ordinary clear glass. It is useful where colour fidelity and high visual clarity are important, such as retail displays and galleries.

Tinted glass absorbs selected wavelengths and can reduce glare or solar gain, but it may increase heat absorption and thermal stress if incorrectly detailed.

4.2 Safety glass

Heat-strengthened glass has greater resistance to thermal stress and mechanical loading than annealed glass, but it is not equivalent to fully tempered glass for safety glazing requirements.

Fully tempered glass is heated and rapidly cooled to create surface compression. It is stronger than annealed glass and, when broken, generally disintegrates into small granular fragments. It cannot normally be cut, drilled, or edge-worked after tempering. It may experience rare spontaneous breakage caused by inclusions; heat-soak testing can reduce, but not eliminate, this risk.

Laminated glass consists of two or more glass plies bonded by an interlayer such as PVB or ionoplast. When fractured, the interlayer tends to retain fragments. Laminated glass is valuable for overhead glazing, balustrades, acoustic applications, security, and fall protection. Interlayer selection affects stiffness, acoustic behaviour, colour, moisture resistance, and long-term performance.

A laminated pane may also be made from tempered or heat-strengthened plies. This combination can provide both post-breakage retention and improved strength, but the complete assembly must be specified and tested.

4.3 Insulating and coated glass

An insulating glass unit (IGU) comprises two or more panes separated by a sealed cavity. The cavity may contain air or an inert gas. Low-emissivity coatings reduce radiative heat transfer. The performance of an IGU depends on pane thicknesses, cavity width, gas fill, spacer design, coating position, frame, edge seal, orientation, and installation quality.

A simplified heat-flow relationship is:

where Q is heat-transfer rate in watts (W), U is thermal transmittance in watts per square metre-kelvin (W/m²·K), A is area in square metres, and ΔT is the temperature difference in kelvins (K). This is a steady-state approximation and does not include all effects of solar radiation, thermal bridging, edge conditions, air leakage, or transient behaviour.

Solar-control coatings can reduce solar heat gain while preserving daylight. However, a dark or highly reflective coating may alter colour rendering, create reflections, or conflict with planning and interior lighting objectives. Performance data should be reviewed rather than inferred from appearance.

4.4 Optical and acoustic performance

Important optical properties include visible light transmittance, reflectance, solar transmittance, colour rendering, haze, distortion, and ultraviolet transmission. Transparency is not identical to high daylight quality: excessive transmission can create glare, visual discomfort, and overheating.

Acoustic performance depends on thickness, mass, air spaces, lamination, framing, and flanking paths. A glass partition will not achieve its laboratory rating if sound bypasses it through a suspended ceiling, floor void, door, or poorly sealed perimeter. Acoustic laminated glass uses a viscoelastic interlayer to improve sound reduction over selected frequency ranges.

5. Glass Safety, Detailing and Codes

The designer must identify locations where human impact, falling, overhead breakage, or containment failure is possible. Typical safety-glazing locations include doors, sidelights, large areas adjacent to doors, low-level glazing, shower enclosures, screens, and balustrades. Exact locations and marking requirements vary by jurisdiction; the applicable building, safety-glazing, accessibility, fire, and occupational regulations must be checked for the project location.

Key principles include:

• Use safety glass where impact is foreseeable.
• Use laminated glass where retention after breakage or fall protection is required.
• Do not assume that tempered glass alone provides a barrier after breakage.
• Provide visible manifestation on transparent doors and screens where required for collision awareness.
• Protect exposed edges from impact and avoid point loads.
• Design supports, clamps, channels, and holes for the specified glass type and tolerances.
• Prevent direct glass-to-metal contact unless the system is specifically designed for it.
• Provide compatible setting blocks, gaskets, packers, and sealants.
• Allow for thermal movement, building movement, fabrication tolerances, and drainage.

Glass should be supported on appropriate setting blocks rather than hard, uneven surfaces. Metal channels must not pinch the glass. Sealants must be chemically compatible with the glass interlayer, coating, gaskets, and adjacent finishes. Edge cover, bite, clearances, and joint dimensions should follow the tested or engineered system rather than an improvised detail.

For balustrades and guardings, the design must address horizontal load, impact, post-breakage behaviour, handrail continuity, opening sizes, anchorage, and the consequences of a broken pane. These are life-safety elements and should be engineered and inspected by competent professionals.

6. Metal–Glass Interfaces

Many interior assemblies combine metal frames with glass: doors, partitions, display cases, shower screens, balustrades, façades, furniture, and lighting features. The interface is vulnerable because glass is brittle while metal can transmit concentrated loads.

Good detailing separates the materials with resilient gaskets or setting compounds, distributes loads, provides drainage, and avoids sharp contact. Stainless steel, aluminium, and glass may be visually compatible but can still experience galvanic or staining problems through fixings and trapped moisture. Sealants should be selected for movement capacity, ultraviolet exposure, cleaning chemicals, and compatibility.

Movement must be accommodated in both materials and in the building. A long metal frame expands with temperature; an inflexible glass panel may crack if the frame closes onto it. The approximate linear thermal expansion can be estimated as:

where ΔL is change in length, α is the coefficient of linear thermal expansion in per kelvin (K⁻¹), L is original length, and ΔT is temperature change in kelvins. The relationship assumes uniform temperature and unconstrained, small thermal expansion. It indicates why long components require clearances and flexible joints.

For example, an aluminium member 2.4 m long with α = 23 × 10⁻⁶ K⁻¹ experiencing a 40 K temperature change expands approximately:

ΔL = 23 × 10⁻⁶ × 2.4 × 40 = 0.002208 m ≈ 2.2 mm.

This movement may be sufficient to stress a rigid glass or tile interface. The calculation is illustrative; the final detail must also consider restraint, solar heating, installation temperature, and tolerances.

7. Selection Framework for Interior Projects

A responsible specification follows a sequence rather than choosing by appearance alone.

1. Define exposure: humidity, water, salt, cleaning agents, pollutants, heat, ultraviolet radiation, abrasion, and impact.
2. Define performance: structural role, fire behaviour, acoustic target, thermal target, privacy, daylight, hygiene, and durability.
3. Choose material family: compare ferrous and non-ferrous options and identify whether a solid material, coating, laminate, or composite is appropriate.
4. Choose grade and thickness: specify recognised standards, temper, finish, and tolerances.
5. Confirm fabrication: verify bending, welding, machining, edgework, drilling, tempering, lamination, and transport constraints.
6. Develop interfaces: coordinate fixings, movement joints, gaskets, sealants, drainage, access, and replacement strategy.
7. Verify compliance: check local building, fire, accessibility, safety-glazing, electrical, environmental, and occupational requirements.
8. Review life cycle: consider embodied carbon, recycled content, repairability, cleaning, replacement, and end-of-life recovery.
9. Approve samples and tests: inspect colour, gloss, texture, edge quality, distortion, visible marks, and assembly tolerances.

A sample is not merely aesthetic. It can reveal galvanic staining, coating adhesion, glass colour, reflection, fingerprints, sealant compatibility, and the visual effect of joints under actual lighting.

8. Illustrative Case: A Humid Hospitality Interior

Background

An illustrative boutique hotel project includes a ground-floor reception area, a glazed lift lobby, a spa corridor, and brass-coloured feature screens. The site has high humidity, frequent cleaning, and substantial public contact.

Problem

The initial concept proposed carbon-steel frames with a painted brass-effect finish, ordinary annealed glass screens, and unisolated stainless-steel fixings. The design risked corrosion, unsafe breakage, finish damage, and staining at wet interfaces.

Analysis

The reception and spa areas involve moisture, cleaning chemicals, abrasion, and human impact. The screen glass is located beside circulation routes, so safety glazing and visual manifestation are required. The brass appearance is desired, but solid brass is not necessary for every component. The team also identifies a risk of water being trapped inside hollow metal sections.

Approach and solution

The revised specification uses stainless steel or suitably protected aluminium in exposed areas, with a tested decorative finish and sample approval. Where a genuine brass surface is required for touch points, solid brass is used and sealed according to the manufacturer’s maintenance system. Laminated safety glass is selected for screens where retention is important; tempered laminated glass is used where greater impact resistance is required. Edges are protected within compatible channels, and setting blocks and gaskets isolate glass from metal.

Drainage paths are provided at low points, and dissimilar metals are separated. Cleaning instructions prohibit chloride-rich products on stainless steel and abrasive pads on decorative finishes. The contractor submits certificates for glass treatment, coating performance, and sealant compatibility. A full-size mock-up is inspected under reception lighting before production.

Outcome

The revised assembly has a more reliable corrosion strategy, safer post-breakage behaviour, better maintainability, and a controlled visual relationship between brass-coloured metal and low-iron glass. The project cost increases modestly at procurement but reduces the risk of early replacement and reputational damage.

Learning points

Material appearance should not dictate material selection without exposure analysis. Safety glazing must be considered at the concept stage. Mock-ups are particularly valuable where reflective metal, transparent glass, artificial lighting, and public contact interact.

9. Sustainability, Ethics and Contemporary Practice

Metals are energy-intensive to produce, but many can be recycled repeatedly without losing their basic material properties. Aluminium recycling can substantially reduce energy demand compared with primary production, although recycled content, alloy separation, coatings, transport, and fabrication still require evaluation. Steel has established recycling streams, while composite or heavily bonded assemblies may be more difficult to recover.

Glass is recyclable, but laminated glass, ceramic frits, coatings, sealants, and mixed assemblies can complicate processing. Designers should favour mechanical disassembly where feasible, document material composition, and avoid unnecessary permanent bonding. Environmental product declarations and life-cycle assessment can support comparison, but results depend on system boundaries and data quality.

Ethical procurement includes responsible labour practices, traceability, avoidance of misleading environmental claims, and transparent disclosure of recycled content and finish durability. Digital fabrication, parametric modelling, automated cutting, and AI-assisted specification tools can improve material efficiency and coordination. They do not replace professional judgement: generated specifications must be checked against standards, manufacturer data, constructability, and actual site conditions.

Challenges and Limitations

No material is universally superior. Stainless steel may resist corrosion but have a high initial cost and visible fingerprints. Aluminium is light but can dent and deflect. Brass provides warmth but tarnishes and may require maintenance. Tempered glass is strong but cannot be modified after treatment and may fail suddenly. Laminated glass retains fragments but can be heavier and more expensive. Coatings improve performance but may conceal substrate defects or be difficult to repair.

Laboratory ratings are not identical to installed performance. A glass partition’s acoustic rating may be defeated by flanking transmission; a coating may fail at cut edges; and a corrosion-resistant metal may deteriorate because of contaminated fixings or poor drainage. Therefore, design decisions should be based on complete assemblies, verified details, competent installation, and planned maintenance.

Chapter Summary

Metals and glass combine technical performance with strong visual influence in interior environments. Ferrous metals, particularly steel, offer strength and economy but require corrosion control. Non-ferrous metals such as aluminium, copper, brass, bronze, and zinc provide lower weight, distinctive appearance, or improved environmental resistance, but each has specific limitations. Alloy grade, fabrication method, finish, exposure, and maintenance must be specified together.

Architectural glass must be selected by manufacture, treatment, safety behaviour, optical properties, thermal performance, acoustics, and location. Tempered glass improves strength and fragmentation behaviour; laminated glass retains fragments and supports security, acoustic, and fall-protection applications. Metal–glass interfaces require compatible materials, resilient separation, movement accommodation, drainage, and engineered fixings. Codes and standards governing safety glazing, fire, accessibility, guarding, and impact must be verified locally. Sustainable and ethical practice requires life-cycle thinking, responsible procurement, repairability, and honest performance claims.

Key Terms

Ferrous metal: A metal whose principal constituent is iron.

Non-ferrous metal: A metal containing little or no iron as its principal constituent.

Alloy: A metallic material composed of a base metal and one or more deliberately added elements.

Stainless steel: Steel containing sufficient chromium to form a corrosion-resistant passive oxide film.

Passivation: Formation or restoration of a protective surface oxide layer.

Galvanic corrosion: Electrochemical corrosion caused by contact between dissimilar metals in an electrolyte.

Anodising: Electrochemical thickening of aluminium’s protective oxide layer.

Powder coating: A thermally cured polymer coating applied as dry powder.

Patina: A surface layer produced by natural or controlled chemical oxidation.

Float glass: Flat glass formed by floating molten glass on molten tin.

Tempered glass: Heat-treated glass with increased strength and characteristic granular breakage.

Heat-strengthened glass: Heat-treated glass stronger than annealed glass but not equivalent to fully tempered glass.

Laminated glass: Glass made from bonded plies with an interlayer that retains fragments after breakage.

Insulating glass unit: Two or more panes separated by a sealed cavity.

Low-emissivity coating: A coating that reduces radiative heat transfer.

Visible light transmittance: The proportion of visible light transmitted through glazing.

Setting block: A resilient support used to position and separate glass from its frame.

Thermal expansion: Change in material dimensions caused by temperature change.

Manifestation: Visible markings applied to transparent glazing to improve collision awareness.

Mock-up: A representative full-size sample used to evaluate appearance, performance, and constructability.

Review Questions

Short Answer Questions

1. What is the principal distinction between ferrous and non-ferrous metals?
2. Why is stainless steel not completely immune to corrosion?
3. State two differences between tempered and laminated glass.
4. What is the purpose of a setting block in a glazed assembly?
5. Name four factors that should be included in a metal finish schedule.

Long Answer Questions

1. Explain how exposure conditions influence the selection of metal alloys and surface treatments in an interior project.
2. Compare float, tempered, heat-strengthened, laminated, and insulating glass in terms of manufacture and application.
3. Discuss the principal causes of failure at metal–glass interfaces and propose suitable detailing responses.
4. Explain why optical performance should be evaluated alongside thermal and energy performance when selecting architectural glass.
5. Discuss how life-cycle thinking can influence the specification of metals and glass.

Analytical / Application Questions

1. A 2.4 m aluminium trim has a coefficient of linear expansion of 23 × 10⁻⁶ K⁻¹ and may experience a 40 K temperature change. Calculate its approximate length change and explain the detailing implication.
2. A designer proposes painted carbon-steel frames and annealed glass for a public spa screen. Analyse the risks and develop a safer, more durable alternative specification.
3. A hotel requires a transparent balustrade beside a busy stair. Recommend a glass and support strategy, identify the information requiring structural-engineering confirmation, and explain the relevant maintenance and inspection issues.

Multiple Choice Questions with Answers

Question 1

Which characteristic most directly distinguishes a ferrous metal from a non-ferrous metal?

A. Its surface colour

B. Iron as its principal constituent

C. Its ability to be polished

D. Its electrical conductivity

Correct Answer: B. Iron as its principal constituent

Question 2

Why is stainless steel generally more corrosion-resistant than carbon steel?

A. It contains a protective chromium-rich passive film

B. It has no metallic elements

C. It absorbs water into its surface

D. It is always coated with paint

Correct Answer: A. It contains a protective chromium-rich passive film

Question 3

Which process is especially associated with producing constant cross-sections in aluminium?

A. Tempering

B. Lamination

C. Extrusion

D. Patination

Correct Answer: C. Extrusion

Question 4

Which glass type is designed to retain many fragments after breakage?

A. Annealed float glass

B. Laminated glass

C. Patterned glass only

D. Tinted glass only

Correct Answer: B. Laminated glass

Question 5

What is a principal limitation of fully tempered glass?

A. It cannot transmit visible light

B. It normally cannot be cut or drilled after tempering

C. It is always weaker than annealed glass

D. It cannot be used indoors

Correct Answer: B. It normally cannot be cut or drilled after tempering

Question 6

In the equation σ = F/A, what does A represent?

A. Acceleration

B. Area

C. Aluminium content

D. Ambient temperature

Correct Answer: B. Area

Question 7

Which measure best reduces galvanic corrosion between dissimilar metals?

A. Trapping water between them

B. Removing all protective coatings

C. Electrically isolating the metals

D. Using thinner metal sections

Correct Answer: C. Electrically isolating the metals

Question 8

What is the principal function of a low-emissivity coating?

A. To increase radiative heat transfer

B. To reduce radiative heat transfer

C. To make glass opaque in every condition

D. To replace safety glazing

Correct Answer: B. To reduce radiative heat transfer

Question 9

Using ΔL = αLΔT, what is the approximate expansion of a 2.4 m aluminium member when α = 23 × 10^-6 K^-1 and ΔT = 40 K?

A. 0.22 mm

B. 2.2 mm

C. 22 mm

D. 220 mm

Correct Answer: B. 2.2 mm

Question 10

Which application most strongly indicates the need for laminated safety glass?

A. A concealed internal cupboard shelf

B. A decorative metal handle

C. A balustrade where retention after breakage is required

D. A solid timber door

Correct Answer: C. A balustrade where retention after breakage is required