BT5 WALL CONSTRUCTION

walls

constructed in different forms and of various materials to serve several functions

exterior walls

protects the building interior from external environmental effects such as heat and cold, sunlight, ultraviolet radiation, rain and snow, and sound, while containing desirable interior environmental conditions

walls

designed to be strong enough to safely resist the horizontal and vertical forces imposed upon them

curtain wall

external, lightweight, non-loadbearing wall that is hung from a metal frame rather than built from the ground like a brick wall

glass curtain walls

designed to span multiple floors and take into consideration design requirements such as: thermal expansion and contraction, water diversion, ventilation, and thermal efficiency

industrial revolution to early 1900s

time when architects expressed the need for an innovative and efficient wall construction system

hallidie building

one of the first buildings with pure glass cutain wall in san francisco, california by james polk

facades

were changed forever with the introduction of the frame building, which permitted a light exterior wall of glass instead of the meagre punched opening of masonry load-bearing walls

piklington

one of the contributors to the development of contemporary glass curtain walls

pilkington planar

the first structural bolt-fixed glass system to be widely marketed developed by alastair pilkington

extruded aluminum frames

frames for the ethereal walls that was introduced in the 1950s

molten tin

pilkington began his experiment using ______________ to support or float the molten glass

float glass

was in full production in 1959

bolting glass

had small metal patches; structural glass

window wall

careful detailing of _______________, bearing on the floor slab, can make it appear as a continuous curtain wall

window wall

generally used to reduce cost; critical that it should be capable of withstanding the wind and seismic loads

structural glass or bolt-fixed glass

series of glass units held together with patches or bolted connections that support the glass by direct bearing and friction

stainless steel

fittings for structural glass or bolt-fixed glass are usually made out of this material

vertical glass fins (mullions) or steel and cable tension structures

lateral supports can be in the form of _________________ and ___________________

extruded aluminum

most common curtain wall frames

aluminum frames

most common are based on either stick or unit system

stick system

installed piece by piece on-site, including the glazing; purchased in 7- to 12-meter lengths and cut on-site or in the shop

unit panel system

series of prefabricated units that interlock with the adjacent frame and is often pre-glazed; may be as high as 3 stories but generally span just one floor and range 4-12ft in width

unit and mullion system

also called the semi-unitized system; hybrid of the stick and unit system; mullions are the first to be installed then the spandrel and glazing are inserted into the stick system as a complete unit

column cover and spandrel system

similar to unit and mullion systems; building frame is emphasized in column covers, which act like sticks

point loaded structural glazing system

vertical member can be comprised of stick, cable, or another custom structure behind the glass; glass is supported by a system of four-point brackets and joints are sealed with silicone

joint

rails and mullions of stick systems each have a _______ on each side that seals the glass to the frame

joint

unitized systems have an additional joint that seals the frame of one unit to the adjoining unit

similar

overall fabrication and installation time is often similar for stick and unitized systems

stick system

can be delivered to the site more quickly but take longer to erect

unitized system

require more lead time but are erected more quickly

annealed glass

standard float glass; not a safety glass

annealing

process of slowly cooling glass to relieve internal stresses after it was formed

tempered glass

strong, break-resistant type of safety glass that, if broken, shatters into small granular pieces

laminated glass

sealed, double-plane glass unit with a vacuum or gas in the space between the panes

float glass

made by floating molten on a bed of molten tin; clearest of the glazing options; transmittance is 75-92% of visible light; slight-greenish tint at a thickness of 10mm or greater

tinted or heat-absorbing glass

has color and light- or heat-reducing capabilities; transmittance is 14-85%

coated glass

glass with a chemical film applied to one surface

solar-reflective or low-emissivity glass

most common coatings used for reflection, absorption and radiation of solar energy

ceramic frit

used to create an opaque or spandrel glass; ceramic coating fused tot the base glass during the heat treating process

fritted glass

required opaque back-up construction

polyester and silicone films and paints

other methods of creating opaque glass

self-cleaning glass

glass with photocatalytic coating that reacts with sunlight to break down and dislodge organic dirt

shadow box

creates the illusion of opacity with a dark metal pan or insulation board that is held bak from the glass

cladding

application of one material over another to provide a skin or layer intended to control the infiltration of weather elements, or for aesthetic purposes

cladding

does not necessarily have to provide a waterproof condition but is instead a control element

lap-seam metal panels

formed out of metal sheets; typically ship-lapped with adjacent panels; gutters or sealant tape are typically included as part of the system

composite metal wall panels

two sheets of metal adhered to a core material; stronger than lap-seam panels and provide built-in insulation to the wall system; often ship-lapped with adjacent panels

foamed-insulation core metal wall panels

has metal facings with insulation foamed into place during fabrication

laminated-insulation core wall panels

has metal facings laminated to preformed insulation boards' can have tongue-in-groove joints for interface with adjacent panels or framed edges where perimeter extrusions attach the panels

honeycomb core metal wall panels

has metal facings bonded to a honeycomb core

flat plate metal wall panels

fabricated out of 1/8 inch thick metal plate then bent to the desire profile; very high impact resistance and durability compared to other types of panels

stiffeners and support structure

can be welded or adhered to the flat plate

metal-faced composite panels

consist of metal facings adhered to a thin thermoplastic core then may be bent to the desired profile; not as impact resistant as flat plates

stiffeners

can be welded or adhered to the rear surface of the metal-faced composite panels

flat plate and metal-faced composite panels

generally less than 10'x10' and fastened by proprietary installation systems

aluminum

corrosion-resistant and comes with a variety of finishes in a wide range of colors

clear anodizing

aluminums should be protected with ____________

colors

produced when electrolic deposition of salts into the microscopic pores of the surface oxide of aluminum

stainless steel

long-lasting and comes in a number of finishes, including high reflectively, smooth, brushed, embossed

light interference

process where deep rich hues which no pain even comes close to are produced

terne coating

has an appearance similar to lead; it's product is called terne-coated stainless steel (tcs)

terne

alloy of lead and tin, with tin helping to bond the lead to the steel

304 alloy of stainless steel

used for standard resistance

316 alloy with molybdenum

for even greater corrosion protection in coastal areas or areas with high pollution levels

steel with various finishes

offers lower cost alternatives but it need protection against corrosion, generally by sacrificial zinc coating

galvanume (zinccalume - TM)

has a hop-dip zinc and aluminum coating and is produced by major steel manufacturers; offers better corrosion resistance than just galvanized steel

spayed sheet metals or coil-coated

sheet metals are sprayed with paint as individual pieces or coil-coated

kynar 500

resist fading and chalking and are "superior" to all other coatings in weatherability; comes in earth tomes

thermoset acrylics

durable and come in a wide range of colors and glosses; cannot be postformed

urethane coatings

come in a wide range of colors and glosses; excellent chemical resistance; fades and chalks to a minor degree

polyester

comes in a variety of colors and high glosses; good durability; widely used

weathering steel

steel in plate form used for cladding

zinc

high corrosion resistance; also comes in preweathered finishes to avoid the transition phase

titanium

popular but costly metal; example is frank gehry's guggenheim museum in bilbao, spain; low coefficient of thermal expansion

titanium

more flexible and weighs less than steel, yet equal in tensile strength and is up to four times as hard as mild steel

insulation

when metal is a non-insulated metal panels are used, it is typically provided by batt insulation set within the stud wall behind the metal panel cladding

air and moisture barrier

may include building papers, house wraps, elastomeric coatings, or peel-and-stick waterproofing membranes

metal stud framing

its design needs to be integrated with the panel design and fastening system

thermal performance

derived from the amount of insulation placed in the cavity within the backup wall

moisture protection

the design of metal panel joints is critical for the watertight performance of the panel system

fire safety

metal panel systems are typically not fire rated systems; mey need to include fire-stopping at floor levels

acoustics

typically do not offer much sound insulation; the back-up wall cavity provides for sound insulation

impact resistance

except for flat plate, metal wall panel systems typically have low impact resistance

material/finish durability

important for system performance; most common finishes applied include flouropolymer, powder and anodized coatings

fluoropolymer and power

provide a wide range of colors as well as color uniformity

anodizing

generally limited to dark metallic colors

coating performance

critical for steel panel quality

porcelain enamel coatings

often used on steel panels and provide good durability but these coatings can be vulnerable to damage in the field

pitting

result when metal panels are exposed to weather and pollution and their protective coating can be attaked

oil canning

pillowing or waviness of the metal panel

shadowing

condition in which the weld or stiffener is visible on the panel face

dissimilar metals

can cause water runoff staining and galvanic corrosion

galvanic corrosion

occurs when one type of metal is in physical contact with another metal

7-20 years

time frame for sealant replacement (depends on the sealant used and joint design)

10 years

time interval for periodic cleaning to mitigate the build-up of pollutants on metal panels

tilt-up construction

construction technique using concrete where modular concrete elements are formed on a concrete slab then after the concrete has cured, elements are tilted from horizontal to vertical with a crane

moulds are designed for a specific building, usually not used

difference of prefabrication and tilt-up construction

steel plates with headed studs

connections to the roof and floors are usually __________________ that studs that were secured into forms prior to concrete placement

insulation

can be applied to either side of the panels or cast inside sandwich