Curtain Wall and Cladding Systems: Glass, Metal, and Tilt-Up Construction

What is the primary function of exterior walls in buildings?

To protect the interior from environmental effects such as heat, cold, sunlight, rain, and sound.

What are the two main types of wall construction systems?

Bearing walls and curtain walls.

What is a curtain wall?

An external, lightweight, non-loadbearing wall hung from a metal frame.

What is the most common material used in curtain wall construction?

Glazing.

What architectural innovation did the Hallidie Building introduce in 1918?

It was one of the first buildings with a pure glass curtain wall.

Who was a key contributor to the development of contemporary glass curtain walls in England?

Alastair Pilkington.

What significant glass technology was introduced in 1959?

Float glass, which allowed for high-quality, economical glass production.

What are the two types of glass curtain wall installations?

Window wall and structural glass.

How does a window wall differ from a continuous curtain wall?

A window wall bears on the floor slab, breaking continuity for barriers and insulation.

What is the primary advantage of stick systems in curtain wall installation?

Lower costs and flexibility in installation.

What is a disadvantage of stick systems?

Field installation of glazing may be done by unskilled workers.

What is a unit panel system in curtain wall construction?

A series of prefabricated units that interlock and are often pre-glazed.

What is one advantage of unit panel systems?

Fabrication in a controlled environment, leading to better quality.

What is a disadvantage of unit panel systems?

Increased cost and complexity in transportation and installation.

What role do aluminum frames play in curtain wall systems?

They provide the structural framework for the curtain wall.

What is the purpose of lateral supports in structural glass systems?

To support the glass through direct bearing and friction.

What are some modern innovations in glass curtain walls?

Glass cubes, curved glass, and various forms of transparent, reflective, and patterned glass.

What historical period saw a global interest in modernism and efficiency in wall construction?

The Industrial Revolution until the early 1900s.

What does the term 'thermal efficiency' refer to in curtain wall design?

The ability to cost-effectively manage heating, cooling, and daylighting in a building.

What is the significance of the Pilkington Planar system?

It was the first structural bolt-fixed glass system widely marketed.

What is the typical height range for unit panel systems?

They may span as high as 3 stories, but generally cover one floor.

What is the impact of temperature and humidity on wall design?

Walls must be designed to accommodate expansion and contraction due to these factors.

What is the primary purpose of a curtain wall in modern architecture?

To provide a lightweight, aesthetic exterior while allowing for large glass surfaces.

What type of loads must curtain walls be designed to withstand?

Wind forces, self-weight, and seismic loads.

What is the role of careful detailing in window wall systems?

To ensure it appears as a continuous curtain wall while managing barriers.

What is the benefit of using prefabricated units in unit panel systems?

It allows for quicker closure of the building and better quality control.

What materials are commonly used in modern curtain wall systems?

Glass, metals, and stone claddings.

What is the purpose of cladding in building construction?

Cladding provides a skin or layer intended to control the infiltration of weather elements and for aesthetic purposes.

What materials are commonly used for metal wall panels?

Metal wall panels are usually fabricated from aluminum, but can also be made from steel, stainless steel, copper, or composite materials.

What are lap-seam metal panels?

Lap-seam metal panels are formed from metal sheets that are typically ship-lapped with adjacent panels and include gutters or sealant tape at the edges.

What is a composite metal wall panel?

Composite metal wall panels feature two sheets of metal adhered to a core material, providing greater strength and built-in insulation.

What is the typical thickness of lap-seam metal panels?

The thickness of lap-seam metal sheets is generally less than 0.05 inches (1.10 mm).

What is the difference between unitized systems and stick systems in curtain walls?

Unitized systems allow for controlled environment installation of glazing units, while stick systems are erected on-site and take longer to install.

What is tempered glass?

Tempered glass is a strong, break-resistant type of safety glass that shatters into small granular pieces when broken.

What is laminated glass?

Laminated glass is a sealed, double-pane glass unit with a vacuum or gas in the space between the panes.

What are the disadvantages of using shiny-coated glass buildings?

Disadvantages include reflected energy adding heat to nearby buildings, glare causing hazards, and confusion for migratory birds.

What is the purpose of using a wet seal in curtain wall systems?

A wet seal is used for maximum water tightness to prevent water infiltration.

What is the role of column covers in column cover and spandrel systems?

Column covers emphasize the building frame and act as sticks in the system.

What is the function of the four-point brackets in point loaded structural glazing systems?

The four-point brackets support the glass and are sealed with silicone.

What is the significance of slope glazing pockets in curtain walls?

Slope glazing pockets help drain water locally and prevent water accumulation.

What is the transmittance range of float glass?

Float glass has a transmittance of 75-92% visible light, depending on thickness and composition.

What is self-cleaning glass?

Self-cleaning glass has a photocatalytic coating that reacts with sunlight to break down and dislodge organic dirt.

What is the purpose of using backup flashing in curtain walls?

Backup flashing is used at the perimeter to prevent water infiltration.

What is the main advantage of unitized systems over stick systems?

Unitized systems can be erected more quickly due to pre-assembly in a controlled environment.

What type of glass is known for breaking into large, sharp pieces?

Annealed glass is known for breaking into large, sharp pieces and is not considered safety glass.

What is the purpose of expansion joints in bronze mullions?

Expansion joints accommodate vertical movement in the structure.

What does tinted or heat-absorbing glass do?

Tinted glass has color added during manufacture to reduce light or heat transmittance.

What is the role of steel brackets in the fastening method of curtain walls?

Steel brackets are used at every floor slab to support the curtain wall system.

What is the primary function of spandrel panels in curtain walls?

Spandrel panels conceal the floor slab and spandrel beam in the curtain wall system.

What is the significance of isolating the curtain wall from building structure movement?

Isolating the curtain wall prevents glass breakage and maintains structural integrity.

What is the typical thickness of a metal sheet used in wall panels?

Generally less than 0.05 inches (1.10 mm)

What is the overall thickness range of composite metal wall panels?

From 1.2 inches to over 2 inches

What are foamed-insulation core metal wall panels?

Panels with metal facings and insulation foamed into place during fabrication.

What are laminated-insulation core metal wall panels?

Panels with metal facings laminated to preformed insulation boards.

What characterizes honeycomb core metal wall panels?

Metal facings bonded to a honeycomb core.

What is a flat plate metal wall panel?

Panels fabricated from 1/8 inch thick metal plate, bent to the desired profile.

What is the impact resistance of flat plate metal wall panels compared to other types?

They have very high impact resistance and durability.

What are metal-faced composite panels?

Panels consisting of metal facings adhered to a thin thermoplastic core.

What is the typical size limitation for flat plate and metal-faced composite panels?

Generally less than 10 feet by 10 feet.

What is aluminum known for in cladding applications?

Corrosion resistance and a variety of finishes in a wide range of colors.

What is the primary disadvantage of stainless steel in cladding?

The initial cost is high, although it is economical in life-cycle cost.

What is Galvanume?

A hot-dip zinc and aluminum coating that offers better corrosion resistance than galvanized steel.

What are Kynar 500 coatings known for?

They resist fading and chalking and are considered superior in weatherability.

What is the thickness of weathering steel plates used for cladding?

0.032 inches (0.813 mm) or greater.

What is the advantage of zinc in cladding?

High corrosion resistance and malleability when combined with titanium and copper.

What is a common backup wall element in metal panel cladding systems?

Insulation, typically provided by batt insulation set within the stud wall.

What is the purpose of an air and moisture barrier in metal panel systems?

To protect against moisture and air infiltration.

What performance issue is critical for the watertight performance of metal panel systems?

The design of metal panel joints.

What is the thermal performance of non-insulated metal panel wall systems derived from?

The amount of insulation placed in the cavity or within the backup wall.

What is a key characteristic of metal panel systems regarding fire safety?

They are typically not a fire-rated system.

What is the role of stiffeners in flat plate and metal-faced composite panels?

They can be welded or adhered to the rear surface for added support.

What is the typical thickness of metal sheets in metal-faced composite panels?

Typically less than 0.05 inches (1.10 mm).

What is the common alloy used for standard resistance in stainless steel?

304 alloy.

Which stainless steel alloy is specified for greater corrosion protection?

316 alloy with molybdenum.

What are thermoset acrylics known for in cladding applications?

Durability and a wide range of colors and glosses.

What is the primary use of polyester in architectural applications?

It is widely used for its variety of colors and good durability.

What is the significance of the light interference process on stainless steel?

It produces deep rich hues that cannot be matched by paint.

Are metal panel systems typically fire-rated?

No, metal panel systems are typically not a fire-rated system.

What must be included in the design of metal panel wall systems for fire safety?

Fire-stopping at floor levels may need to be included.

Do insulated and composite panel systems require review for flammability?

Yes, to verify that the insulation and thermoplastic cores are not flammable.

How do metal panel systems perform in terms of sound insulation?

They typically do not offer much sound insulation, except for some insulated panels.

What is the impact resistance of most metal wall panel systems?

They typically have low impact resistance and can be damaged by impact loading.

What types of finishes are commonly used on metal panels?

Fluoropolymer, powder, and anodized coatings.

Which material has high corrosion resistance among metal panels?

Stainless steel, copper, and aluminum.

What happens if the coating on a mild steel panel fails?

The panel will start to corrode.

What is pitting in metal panels?

Pitting is a condition where the protective coating is attacked, resulting in a pitted appearance.

What causes oil canning in metal panels?

Problems in fabrication, design, or installation can cause oil canning, characterized by pillowing or waviness.

What is shadowing in metal panels?

Shadowing occurs when welds or stiffeners on the backsides of panels are visible on the panel face.

What problems can arise from using dissimilar metals in metal cladding?

Water runoff staining and galvanic corrosion.

What is the recommended maintenance for metal panel systems?

Periodic cleaning and sealant replacement, typically every 7 to over 20 years.

What is tilt-up construction?

A construction technique using concrete where modular elements are formed on a slab and then tilted into position.

How are concrete elements prepared in tilt-up construction?

They are formed on a concrete slab and then tilted from horizontal to vertical with a crane.

What is the difference between tilt-up construction and prefabrication?

Tilt-up uses molds designed for a specific building and usually not reused.

What materials are typically used for forms in tilt-up construction?

High-quality plywood, fiber board, aluminum, or steel.

What is the purpose of a bondbreaker in tilt-up construction?

To prevent the cast concrete from bonding with the form or slab.

What is a critical step in the tilt-up construction process?

Proper selection and application of the bondbreaker chemical.

What is the typical width range for panel sizes in tilt-up construction?

Panel widths can be sized from 180mm to 650mm.

What is the significance of joint design in metal panel systems?

Joint design affects the performance and aesthetics of the panel system.

What is the typical spacing between horizontal panels in metal cladding?

A 25mm space is commonly shown between horizontal panels.

What can happen if dirt and pollutants are not periodically cleaned from metal panels?

They may attack the panel coating system and cause pitting.