Glossary

AAMA
American Architectural Manufacturers Association. The leading trade association representing window, door, skylight, curtain wall and storefront manufacturers and their suppliers. Responsible for, among others, AAMA 508 and 509.
AAMA 501.2
Quality Assurance and Diagnostic Water Leakage Field Check of Installed Storefronts, Curtain Walls, and Sloped Glazing Systems. A field check procedure for those storefronts, curtain wall cladding systems and sloped glazing systems designed to remain permanently closed and water tight.
AAMA 508
Voluntary Test Method and Specification for Pressure Equalized Rain Screen Wall Cladding Systems. A prescriptive specification and test method which establishes the requirements for test specimens, apparatus, test procedures, test reports and minimum performance criteria for pressure-equalized cladding systems.
AAMA 509
Voluntary Test and Classification Method for Drained and Back Ventilated Rain Screen Wall cladding Systems. A descriptive test and classification method which establishes the requirements for test specimens, apparatus, test procedures, test reports and performance data that may be used in the evaluation of drained/back-ventilated wall cladding systems.
AAMA 2604
Voluntary Specification, Performance Requirements and Test Procedures for High Performance Organic Coatings on Aluminum Extrusions and Panels. A specification which describes test procedures and performance requirements for high performance organic coatings applied to aluminum extrusions and panels for architectural products.
AAMA 2605
Voluntary Specification, Performance Requirements and Test Procedures for Superior Performance Organic Coatings on Aluminum Extrusions and Panels. A specification which describes test procedures and performance requirements for superior organic coatings applied to aluminum extrusions and panels for architectural products.
ACM
Aluminum composite material. A flat cladding material that consists of two thin aluminum sheets chemically bonded to a non-aluminum (e.g. thermoplastic) core. Frequently used as vertical cladding, signage, embellishments and column covers. Even larger spans (e.g. 4’-0” or more) are resistant to oil-canning.
Air Barrier Material
The building component designed and constructed to provide the principal plane of airtightness through the environmental separator (normally required to have an air permeance rate no greater than 0.02 L/(s•m²) at a pressure difference of 75 Pa when tested in accordance with ASTM E2178). Key to long-term air barrier performance is a dew point analysis. (Distinguished from air/thermal barrier.)
Air/thermal barrier
The plane along which principal environmental separation of air and temperature occurs. To be distinguished from air barrier material and insulation.
Aluminum plate
Solid, rolled aluminum stock, in 0.250-inch thickness or greater.
Aluminum sheet
Solid, rolled aluminum stock, in 0.249 to 0.006-inch thickness.
Anodizing
An electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. Anodizing increases corrosion resistance and wear resistance, and provides better adhesion for paint primers and glues than does bare metal. Anodizing can also be used for a number of cosmetic effects, either with thick porous coatings that can absorb dyes or with thin transparent coatings that add interference effects to reflected light.
Architectural
Exhibiting sufficient performance criteria and visual appeal for use in the interior or exterior of commercial construction. Often distinguished from industrial products.
Architectural mesh
A flexible or rigid stainless steel weave, meant for privacy, shading, or embellishment.
ASHRAE
American Society of Heating, Refrigerating and Air-Conditioning Engineers. A building technology society with which, along with its members, emphasizes building systems, energy efficiency, indoor air quality, refrigeration and sustainability within the construction industry. Responsible for, among others, ASHRAE 90.1.
ASHRAE 90.1
Energy Standard for Buildings Except Low-Rise Residential Buildings. First published in 1975, ASHRAE 90.1 establishes minimum energy efficiency requirements of buildings, other than low-rise residential buildings. Notable for its detailed U-value and ci prescriptions per climate zone.
ASTM
ASTM International, formerly known as American Society for Testing and Materials. Responsible for, among others, ASTM D4214, D2244, and E84.
ASTM D4214
Standard Test Methods for Evaluating the Degree of chalking of Exterior Paint Films. A common test method which evaluates the degree of chalking on white or tinted exterior paint films.
ASTM D2244
Standard Practice for Calculation of Color Tolerances and Color Differences from Instrumentally Measured Color Coordinates. A common test procedure for determining color consistency between test and control samples.
ASTM E84
Standard Test Method for Surface Burning Characteristics of Building Materials. A common industry procedure for determining the comparative surface burning behavior of building materials, applicable to exposed surfaces such as walls and ceilings.
ASTM E96
Standard Test Methods for Water Vapor Transmission of Materials. A common industry procedure for obtaining, by means of a simple apparatus, reliable values of water vapor transfer through permeable and impermeable materials, expressed in suitable units.
ASTM E119
Standard Test Methods for Fire Tests of Building Construction and Materials. A common industry procedure for evaluating the duration for which tested assemblies contain a fire, retain their structural integrity, or exhibit both properties during a predetermined test exposure.
ASTM E283
Standard Test Method for Determining Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen. A common industry procedure for determining the air leakage characteristics under specified air pressure differences at ambient conditions.
ASTM E330
Standard Test Method for Structural Performance of Exterior Windows, Doors, Skylights and Curtain Walls by Uniform Static Air Pressure Difference. A common procedure for determining structural performance under uniform static air pressure difference.
ASTM E331
Standard Test Method for Water Penetration of Exterior Windows, Skylights, Doors, and Curtain Walls by Uniform Static Air Pressure Difference. A common procedure for determining the resistance to water penetration under uniform static air pressure differences.
ASTM E1886
Standard Test Method for Performance of Exterior Windows, Curtain Walls, Doors, and Impact Protective Systems Impacted by Missile(s) and Exposed to Cyclic Pressure Differentials. A test method which measures the ability of building envelope components to remain unbreached during a windstorm.
ASTM E1996
Standard Specification for Performance of Exterior Windows, Curtain Walls, Doors, and Impact Protective Systems Impacted by Windborne Debris in Hurricanes. A test method which measures the ability of building envelope components to remain unbreached during a hurricane.
ASTM E2178
Standard Test Method for Air Permeance of Building Materials. A common test method which measures the air permeance of flexible sheet or rigid panel-type materials.
Baffle
A device meant to obstruct the flow of gas, liquid, sound, or light. Example: a joint baffle.
Barrier
The plane along which principal environmental separation of air occurs.
Barrier system
A one-leaf principle for designing wall assemblies, in which the cladding is integral with the air/thermal barrier, or in which the interior cavity is not considered a true drainage plane.
Chalking
A coating defect during which a powdery surface forms due to the disintegration of the surface binder or elastomer. Chalking is caused by weathering, fuel, or other destructive environmental factors and results in a loss of gloss. Often measured in accordance with ASTM D4214.
Chemical bond
An attraction between atoms that allows the formation of chemical substances that contain two or more elements.
Cladding
The covering of a structure.
Climate zones
A U.S. Department of Energy classification system which specifies seven distinct regions, for purposes of establishing unique energy efficiency requirements for each region.
CNC
Computer numerical control; i.e. the automation of machine tools operated by programmed commands as opposed to controlled manually via handwheels or levers, or mechanically automated via cams alone.
Coil-coating
The process by which paint is deposited by a series of rubber rollers into a thin film of coating onto a continuous sheet of metal or plastic. After coating, the sheets are rolled into coils for manufacturing. (See also toll coating.)
Cold bridging
The phenomenon of heat loss through an otherwise insulated wall assembly, due to contacting conductive materials. Similar to thermal bridging.
Condensation
Water that collects as droplets on a cold surface when humid air is in contact with it.
Continuous insulation
Thermal barrier material installed to the exterior side of stud or wood framing, with a minimum of penetrating fasteners and no thermal bridging or interruptions, except for service openings. (Also known as ci.)
Corrosion
The gradual destruction of a material, usually metal, by a chemical reaction with its environment.
Copper
A natural metal and an element (atomic number 29), used primarily in architectural applications as profile roofing, shingles, flashing and dormers. Copper is known for its dramatic shift in patina over decades of use.
Deflection
Any deviation—permanent or temporary—from plumbness, alignment, or elevation, especially after installation and when caused by building loads or material expansion/contraction. When used to describe individual parts, deflection may indicate perimeter, main field or anchors. Not to be used synonymously with oil-canning.
Dew point
The temperature of a surface at which condensation will occur, given ambient temperature and relative humidity.
Drainage plane
An uninterrupted vertical cavity between the interior side of the cladding and the exterior side of the back-up wall, meant primarily for moisture control. The drainage plane varies in depth with cladding type, building geometry, and design loads.
Drained/Back-ventilated rainscreen
The rainscreen application governed by AAMA 509. In principle, the cladding is open at top and bottom, and intermediate joints may be closed, partially open, or fully open. Bulk water is channeled through the drainage plane and shed at the base of system, while the stack effect dries any residual moisture.
Dry system
A route-and-return application in which continuous interlocking extrusions with wiper gaskets are secured to the perimeter of each panel (also known as a gasketed system). The system is in turn mounted to support tracks and, if necessary, to stud bridging.
Fading
A coating defect because of which gloss or sheen is lost. Often measured in accordance with ASTM D2244.
FEVE
Fluoroethylene vinyl ether. The first solvent-soluble fluoropolymer for coatings that can be cured under room temperature conditions. Trademarked as Lumiflon.
Flame Spread Index
A measure of the flammability of test material in relation to the red oak standard (as defined by ASTM E84).
Flame-retardant
Any material used to inhibit or resist the spread of fire. In domestic ACM manufacture, flame-retardant cores are tested to more stringent fire classification methods, such as NFPA 285.
Flashing
A thin piece of impervious material installed to prevent the passage of water into a structure from a joint. Because of its complex profiles and critical role in construction assemblies, flashing must be malleable, strong and solderable, and is therefore commonly fabricated from single-skin metals.
Flush panel
A flat, roll-formed, single-skin cladding material. Profiles are generally concealed, although the material face may or may not exhibit embossing patterns.
Galvanizing
A zinc coating intended for corrosion resistance.
HPL
High-pressure laminate. A flat cladding material that consists of layers of paper and resin, molded and cured under pressures in excess of 1,000 PSI.
IECC
International Energy Conservation Code (e.g. IECC 2012). A model code published by the ICC, adopted by many states and municipal governments for the establishment of minimum design and construction requirements for energy efficiency in new buildings.
Impermeable
Not allowing fluid to pass through. Per ASHRAE 90.1 any air barrier with a U.S. perm rating of 0 to 0.1 is “vapor impermeable,” when tested to ASTM E96.
Insulation
Any building material used to achieve thermal comfort. (See also continuous insulation)
Joint
The mating feature between two materials of similar or adjacent systems (also known as joinery).
Mass wall
An above-grade wall weighing not less than (1) 35 pounds per square foot of surface area or (2) 25 pounds per square foot of surface area when the material weight does not exceed 120 pounds per cubic foot (as defined by IECC 2012). Examples include concrete, block, insulated concrete forms, masonry cavity, brick (other than veneer), earth and solid timber.
MCM
Metal composite material. A flat cladding material that consists of two thin metal sheets chemically bonded to a non-metal (e.g. thermoplastic) core. Frequently used as vertical cladding, signage, embellishments and column covers. Skin types include stainless steel, copper and zinc alloy.
Metal building wall
A wall whose structure consists of metal spanning members supported by steel structural members (i.e., does not include spandrel glass or metal panels in curtain wall systems) (as defined by ASHRAE 90.1).
Mil
0.001-inch. A typical manufacturing dimension, often used to specify paint thicknesses.
Model code
A building code that is developed and maintained by a standards organization independent of the jurisdiction responsible for enacting the building code.
Natural metals
A subjective term used generally to denote non-painted metals such as stainless steel, zinc, and copper. Most definitions of natural metals allow for compounds, alloys, anodized and pigmented materials.
NFPA
National Fire Protection Association. A trade association aimed at reducing the worldwide burden of fire and other hazards on the quality of life by providing and advocating consensus codes and standards, research, training, and education. Responsible for, among others, NFPA 285.
NFPA 285
Standard Fire Test Method for Exterior Non-load-bearing wall Assemblies Containing Combustible Components. NFPA 285 is performed using a two-story chamber called the Intermediate-Scale, Multi-Story Test Apparatus and is intended to simulate a tested wall assembly’s fire performance.
Non-progressive installation
A cladding system that allows removal of one or more panels without removal, relocation, modification or demolition of any adjacent panels, regardless of building geometry. Most effective for applications requiring access panels or on projects experiencing frequent vandalism.
Oil-canning
Perceived waviness in the flat areas of metal roofing and metal siding panels. Oil canning is an inherent part of light gauge roll-formed metal products, particularly those with broad flat areas. When used to describe individual parts, oil-canning generally indicates the main field only. For this reason—and given the fact that oil-canning is not a structural concern—the term is not to be used synonymously with deflection.
Patina
A layer of tarnish that forms on the surface of copper, zinc and similar metals, often produced naturally by oxidation. Patina varies by element and alloy.
Permeable
Allowing fluid to pass through. Per ASHRAE 90.1 any air barrier with a U.S. perm rating of greater than 10 is “vapor permeable,” when tested to ASTM E96.
Post-finishing
The process by which paint is deposited to primed, manufactured material, e.g. aluminum sheet and aluminum plate (also known as spray-applied).
Pressure-equalized rainscreen
The rainscreen application governed by AAMA 508. In principle, the cladding is compartmentalized and vented, eliminating any water infiltration due to pressure gradients. Residual moisture is channeled through the drainage plane and shed at the base of compartment.
Profile panel
Any roll-formed single-skin cladding with repeating rib patterns.
PVDF
Polyvinylidene fluoride. In the manufacture of architectural materials, fine powder grades of PVDF (e.g. Kynar 500 and Hylar 5000) are used as the principal ingredients of high-end metal finishes.
Rainscreen
A two-leaf principle for designing wall assemblies, in which the cladding is separated by the air/thermal barrier by an uninterrupted drainage plane.
Roll-forming
A continuous bending operation in which a coil or strip of sheet metal is passed through sets of rolls mounted on consecutive stands. Roll forming is ideal for producing constant-profile parts with long lengths and in large quantities. (See also toll forming.)
Route-and-return
An ACM fabrication technique in which panel perimeters are folded into perpendicular flanges, to which extrusions are fastened and—in the case of wet systems—sealant is adhered. With flanges, the folded ACM panel is typically 1” deep and referred to as a pan.
R-value
The ratio of the temperature difference across an insulator to the heat flux, under uniform conditions. Also defined as the multiplicative inverse of the U-value.
Smoke Developed Index
A measure of the airborne particles produced by burning test material, in relation to the red oak standard (as defined by ASTM E84).
Spline
In construction, a joint closure for any cladding system.
Stainless steel
One of any forms of steel containing chromium. Stainless steel is known for its durability, corrosion resistance and high solar reflectivity.
Steel-framed wall
A wall with a cavity (insulated or otherwise) whose exterior surfaces are separated by steel framing members (as defined by ASHRAE 90.1).
Standard
In construction, a test method used as a basis for comparing material performance.
Stud bridging
Miscellaneous furring profiles or strips intended on providing mechanical attachments between design members, often designed and fabricated on site.
Thermal bridging
The phenomenon of heat transfer through an otherwise insulated wall assembly, due to contacting conductive materials. Similar to cold bridging.
Thermoplastic
Substances, especially synthetic resins, that become plastic on heating and harden upon cooling, and are able to repeat these processes.
Toll
A compensation for products or services. In the manufacture of architectural materials, toll coating or toll forming refer to custom work by third party suppliers, in which the buyer provides the coil and specifications.
U-value
The ratio of the heat flux to the temperature difference across an insulator, under uniform conditions. Also defined as the multiplicative inverse of the R-value.
U.S. perm rating
The measure of the diffusion of water vapor through a material. A U.S. perm rating of one is equal to one grain of water vapor per hour, per square foot, per inch of mercury.
Wall
That portion of the building envelope, including opaque area and fenestration, that is vertical or tilted at an angle of 60° from horizontal or greater (as defined by ASHRAE 90.1).
Wet system
A route-and-return application in which interlocking extrusions (normally continuous) are secured to the perimeter of each panel. The system is in turn mounted to support tracks and, if necessary, to stud bridging. Panel joinery is face-sealed with caulking.
Zinc
A natural metal and an element (atomic number 30), used primarily in architectural applications as profile roofing, flush panels, and residential gutters. Zinc is known for a patina that allows self-healing of some surface damage.
Zinc alloy
An electroplated combination of zinc with at least one other metallic elements, normally intended for improved strength, corrosion resistance or aesthetic appeal.