Skip to main content

Glazing Glossary

Anodized Metal Finishes#

A finish for metals in which the surface is coated with a layer of oxide through an electrolytic process. The coating can be for protective or decorative reasons. (Source: Glass Magazine, May 2010. ​

Butt-Joint Glazing#

A wall system that provides supporting mullions at the head and sill, while the vertical dimensions are unsupported. Butt-joint glazing systems provide two-sided support for glass and may incorporate a silicone joint, or mechanical clip, between the lites of glass to decrease glass vibration and deflection. (Source: Glass Magazine, May 2010. ​

Curtain Wall#

An exterior, non-load-bearing wall system that utilizes glass – either transparent or spandrel, or both – and vertical and horizontal mullions acting as structural members to transfer wind and gravity forces to the building structure. The system is anchored to, and supported by, the structural members of the the building. There are two types of curtain wall systems: stick and unitized. (Source: Glass Magazine, May 2010.

Stick Curtain Wall#

Consists of the curtain wall frame verticals (mullions) and glass or opaque panels that are installed and connected piece by piece. These parts are usually fabricated and shipped KD (knocked down) to the job site for installation.

Unitized Curtain Wall#

Comprised of large units that are assembled and glazed in the factory. They are then shipped to the job site and erected on the building faΓ§ade. ​

Dead Load#

The vertical load due to the weight of all permanent structural and non-structural components of a building, such as walls, floors, roofs, and fixed service equipment. ​

Dry Glazing#

A method of securing g[ in a frame that uses preformed, resilient gaskets instead of a wet sealant or glazing compound. ​


A framing member or other type of component formed by forcing aluminum or vinyl through a shaped opening. ​


Metal or other suitable material placed to shed water.

Flush Glazing#

A system of installing glass in which the member that holds the glass in place (the glazing bead) is recessed within and flush with the edge of the frame. These Systems are also called "pocket-glazed" and "center-glazed" systems. ​


The horizontal member that forms the top of a frame. ​

Inside Glazing#

A method in which glass is secured in an opening from the interior of the building.

Insulating Glass#

An integral glass unit made up of two or three individual lites of glass separated by an air space.


One of two vertical members of a door or window frame.


An abbreviation for "knock down."


The condition of perfect horizontal alignment. ​


A horizontal structural member that spans an opening at the head to carry the weight of construction above the opening. ​

Miter Joint#

A joint made up of two members each of which is cut at one-half the total angle of the joint. ​


An intermediate, vertical or horizontal framing member. ​

Organic Coatings#

Paint or powder coatings that are factory applied and include some type of resin. A common resin for exterior applications is Polyvinylidene Fluoride, PVDF, because of its weatherability. Liquid paints are composed of pigment, resin and solvent. Powder paint is pigment encapsulated in a powdered resin. (Source: Glass Magazine, May 2010. ​

Outside Glazing#

A method in which glass is secured in an opening from the exterior of the building. ​


The condition of perfect vertical alignment. ​

Pocket Filler#

An extrusion that snaps into a mating vertical or horizontal member to provide a glazing pocket. ​

Point-Supported Glass#

A glass wall system without mullions. Individual lites of glass are attached to the building structure with fittings connected through holes in the glass. (Source: Glass Magazine, May 2010. ​

Pressure Plate#

In certain glazing Systems, a member that bolts to a mullion to secure the glass. Pressure plates are usually concealed by a cover that snaps onto them. ​

Punched Windows#

Individual window units that are β€œpunched” into a building elevation and surrounded by non-fenestration facade materials like brick, stone, cement, or wood. (Source: Glass Magazine, May 2010. ​


The channel placed at the head and sill in certain types of glaring systems that hold the vertical mullions. Sometimes called β€œcans.” ​

Screw Spline#

A type of joinery that uses a two-piece, snap-together mullion. The splines are extruded into the female framing member and receive a special type of fastener. ​

Setting Block#

A small piece of neoprene, EPDM rubber, silicone, or other material placed in a frame to distribute the weight of the glass, to center the glass vertically within the frame, and to prevent glass-to-metal contact. ​

Shear Block#

A type of joinery that uses a clip (the shear block) attached to a vertical mullion. The horizontal member fits over the clip and is secured to it by screws driven into the shear block ​


A spacer of uniform thickness and varying sizes used to plumb and level frames. ​


The glazed frame or frames placed on one or both sides of a door. ​


The bottom member of a framing system. ​

Steel Reinforcing#

A steel component placed within a vertical mullion to add stiffness and increase the wind load capability of the system. ​


A non-residential system of doors and windows mulled as a composite structure; typically designed for high use/abuse and strength. (Source: Glass Magazine, May 2010. ​

Thermal Break#

An insulating material of low thermal conductivity placed between materials of high thermal conductivity within the system itself to inhibit the flow of cold or heat. ​

Weep Role#

A small opening in the sill that allows infiltrated water to drain out of the frame. ​

Wet Glazing#

A method of securing glass in a frame that uses sealants or glazing compounds instead of preformed, resilient gaskets. ​

Wind Load#

The force generated by the wind on a framing system. ​

Window Wall#

Also referred to as strip window or horizontal ribbon window, windows form a continuous horizontal band along an elevation of a building. They can be fixed or operable windows with vertical and horizontal framing members and glass in-fills. (Source: Glass Magazine, May 2010.