Glossary of Terms | Letter "A"

Below is a list of some of the most common terms in the window and door industry.

Above-Grade: The portion of a building that is above ground level.
Acrylic: A thermoplastic material used in glazing.
ADA-Compliant Sill: This is a door sill no more than 1-1/2 tall to allow for easy wheelchair access. It complies with the Americans with Disabilities Act.
Adams Casing: This is a type of decorative exterior trim that’s applied to wood or clad-wood windows and patio doors.
Adhesive Failure: Loss of bond of a coating or sealant from the surface to which it is applied.
Aerogel: Currently under development for potential use as a glazing cavity-fill material, aerogel is a microporous, transparent silicate foam that offers very high thermal performance.
Air Infiltration: This test measures air infiltration through a window or door, excluding air which passes between the frame of the unit and the wall. The units are tested as specified in AAMA/NWWDA 101/I.S.2-97: cfm (cubic feet/minute) per square foot of overall frame dimension.
Air Infiltration: The amount of air leaking in and out of a building through cracks in walls, windows and doors.
Airspace Grilles: See grilles between the glass.
Airspacer: This component is placed at the perimeter of an insulating glass unit to separate the two lites of glass.
Alder: This versatile wood species features a fairly straight grain with areas of burl clusters and a few small knots. These marks add character to the door and will provide darker texture and color when finished. Alder varies from pale yellow to reddish brown, and it accepts stains exceptionally well.
Aluminum: A malleable metallic element, bluish silver-white in color, that has good electrical and thermal conductivity, high reflectivity, and resistance to oxidation. It is the most abundant metal in the earth's crust.
Aluminum Cladding: Jeld-Wen durable aluminum cladding provides a protective shell on the exterior surfaces of their wood windows and patio doors. It's available in many eye-catching colors and offers excellent resistance against scratches, cracking, blistering, and flaking. It may be extruded aluminum or roll formed.
American Architectural Manufacturers Association (AAMA): This trade association is the source of performance standards, product certification and educational programs for the window, door and skylight industry.
American National Standards Institute (ANSI): A clearinghouse organization for all types of standards and product specifications.
American Society for Testing and Materials (ASTM): See ASTM International.
American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE): A national association that establishes standards for building energy performance.
Annealed Glass: This is standard float glass before it is treated for additional heat strengthening or tempering. Annealed glass is not safety glazing.
Anodize: A treatment process to apply a protective coating to bare aluminum.
Anti-Lift: An anti-lift is a stop applied in the track of a sliding window or patio door to keep the sash or panel from being lifted out from the outside.
Antique Glass: Subtle texture gives this glass a slightly obscure look that still admits plenty of light.
Applied Nailing Fin: This is a mechanically attached vinyl fin frequently folded against the cladding. See also nailing flange.
Apron: An apron is an interior trim component installed below the stool of a window.
Arch Top Window: See radius window.
Argon: This is a colorless inert gas that is injected in the airspace of an insulating glass unit to improve energy efficiency.
ASTM International: Formerly the American Society for Testing and Materials, this organization establishes material standards (including glass) and test methods. It has also produced a window installation standard.
Astragal: The vertical trim attached to one of the sash of a French casement window or one of the panels of a French door that bridges the gap between the sash/panels when closed to provide weather and overswing protection.
AuraLast® Wood: Solid pine AuraLast wood provides superior protection against wood decay, water saturation and termites. It's also backed by a 20-year warranty.
Awning Window: A window with a sash that is hinged at the top and opens from the bottom.
Azurlite Glass: This blue- tinted glass is popular in regions where shading is desired.