CHAPTER 21

Flashcards about cladding with metal and glass, focusing on aluminum, framing systems, water management, glazing, double-skin facades, and metal panel cladding.

Aluminum

Light in weight and strong, protects itself against corrosion, can be fabricated into elaborate, precise shapes, accepts and holds a variety of surface finishes.

Aluminum Production

Extracted from bauxite ore through a smelting process to remove oxygen.

3xxx Aluminum Alloy Series

Manganese, Cold working, Sheet and plate

5xxx Aluminum Alloy Series

Magnesium, Cold working, Anodize Sheet and plate

6xxx Aluminum Alloy Series

Silicon, magnesium, Heat treatment, Extruded shapes

Aluminum Alloy Description

A four-digit alloy number followed by a temper designation identifying the processes used to control strength, hardness, corrosion resistance, and other mechanical properties.

Aluminum Extrusion

Process where heated aluminum is pushed through a shaped die to create intricate sections.

Extruded Aluminum Sections

Used for curtain wall components, door frames, window frames, handrails, grillwork, and structural shapes.

Aluminum Extrusion Fastening

Achieved through screw ports parallel to the extrusion, screw slots perpendicular to the extrusion, and snap-together parts.

Aluminum Thermal Conductance

Aluminum conducts heat 4 times faster than ordinary steel.

Thermal Breaks in Aluminum Framing

Reduce heat flow through framing members and improve thermal performance.

Types of Thermal Breaks

Pour and debridge and Polyamide strip.

Anodizing

Manufacturing process that produces a protective oxide layer on aluminum to prevent corrosion and allow coloring. Very hard, excellent resistance to weather and fading.

Fluoropolymer Coatings

High-performance finish for aluminum, longest lasting, made of special plastics (PVDF) and (FEVE).

Powder Coatings for Aluminum

Low cost, durable, applied with electrostatic charge.

Baked Enamel Coatings for Aluminum

Inexpensive, broad color choice.

Types of Aluminum and Glass Framing Systems

Storefront (low-rise), Curtain wall (high-rise), Window wall (window/curtain wall hybrid).

Storefront Framing System

Least costly, simple extrusion shapes, spans between floors, mostly used at ground floors, modest height limits.

Curtain Wall Framing System

Hangs off of the floor edges, more complex construction, designed to resist higher wind pressures and water penetration, suitable for buildings of any height.

Window Wall Framing System

Spans between floors like storefront, designed for higher wind pressures, suitable for use on taller buildings, can mimic the appearance of curtain wall at lower cost.

Modes of Curtain Wall Assembly

Stick System and Unit System.

Stick System Assembly

Assembled from parts on the building, low shipping bulk, easy adjustability to site conditions, but must be assembled piece by piece on site.

Unit (or Unitized) System Assembly

Assembled into units in the factory then shipped to the building site and lifted into place on the building side, installation takes place solely from the interior, minimizes labor on the construction site, best suited to large buildings with regular configurations.

Storefront Assembly

Stick-built.

Curtain Wall Assembly

Either stick-built or unitized.

Window Wall Assembly

Mostly prefabricated (unitized).

Water Management in Framing Systems

Most aluminum and glass framing systems are designed as drained systems.

Water Management in Storefront and Window Wall

Water that passes exterior glazing seals drains downward to the bottom of the framing where it is captured by the subsill.

Water Management in Curtain Wall

Water that penetrates the glazing seals flows toward the horizontal mullions, sealed plugs at the ends prevent water from draining downward.

Movement Allowance in Curtain Wall

Vertical mullion splices allow for movements due to thermal expansion and contraction of aluminum or building structure deflection or creep.

Movement Allowance in Storefront and Window Wall

Head receptors allow for vertical movement between structure and aluminum framing.

Outside Glazed Framing System

Glass is installed from scaffolding outside the building.

Inside Glazed Framing System

Glass installation is performed from the inside.

Storefront Glazing

Outside glazed.

Curtain Wall Glazing

Some outside, some inside.

Window Wall Glazing

Some outside, some inside.

Double-Skin Facade

Constructed of two glass cladding systems separated by an airspace.

Benefits of Double-Skin Facades

Can reduce unwanted heat gains, increase daylighting potential, provide a protected space for shading elements, permit natural ventilation designs in tall buildings.

Architectural Sheet Metal Cladding

Thin sheets require closely spaced joints to hold sheets flat.

Formed Metal Panels

With deeper profiles, are stiffer and are installed with exposed fasteners.

Metal Plate Cladding

Made from stiffer, thicker panels and concealed fastening.