GLOSSARY OF REPLACEMENT WINDOW TERMS.

When replacing the windows and doors in your home, you may hear a number of terms and phrases that are unfamiliar. Nobody should make you feel uncomfortable by using language that leaves you wondering what they mean. Here are some terms that you should become familiar with…

• Bay Window

A composite of three windows, usually made up of a large center fixed unit and two flanking units at 30°, 45° or 90° angles to the wall.

• Beveled Exterior

An angled extension from the frame that adds an aesthetically-pleasing dimension to the exterior of the window.

• Block Frame Window

Used when replacing the wood sash of an old double hung wood window.

• Bow Window

A composite of four or more window units in a radial or bow formation.

• Cam Lock and Keeper

The mechanisms which pull the sash together when placed in the locked position.

• Casement Window

A window unit in which the single sash cranks outward, to the right or left.

• Casing

Molding of various widths, thickness and shapes applied to the framework of window units.

• Caulk

A mastic compound for filling joints and sealing cracks to prevent leakage of water and air, commonly made of silicone, bituminous, acrylic, or rubber-based material.

• Conduction

Energy transfer from one material to another by direct contact.

• Convection

Heat transfer by currents that flow from a warm surface to a colder one.

• Dormer

A space which protrudes from the roof of a house, usually including one or more windows.

• Double-hung Window

A window unit that has two operable sashes which move vertically in the frame.

• Drip Cap

A molding placed on the top of the head brickmold or casing of a window frame.

• Double or Dual Glazing

Use of two panes of glass in a window to increase energy efficiency and provide other performance benefits.

• Emissivity

The relative ability of a surface to radiate heat.

• Fenestration

An architectural term referring to the arrangement of windows in a wall. From the Latin word, “fenestra,” meaning window.

• Frame

The enclosure in which a window sash is mounted.

• Glazing

Glass in a window or door; the act or process of fitting with glass.

• Glazing Bead

A plastic or wood strip applied to the window sash around the perimeter of the glass.

• Glazing Stop

The part of the sash or door panel that holds the glass in place.

• Head

The main horizontal member forming the top of the window frame.

• Header

A horizontal framing member placed over the rough opening of a window to prevent the weight of the wall or roof from resting on the window frame.

• Inert Gas

Safe, odorless, colorless, non-toxic, non-flammable gas that is commonly used in place of air between the glass panes of an insulated Low-E glass unit to reduce temperature transfer. Usually either argon or krypton gas.

• Insulating Glass

A combination of two or more panes of glass with a hermetically sealed air space between the panes of glass. This space may or may not be filled with an inert gas, such as argon.

• Jamb

The main vertical members forming the sides of a window frame.

• Lineal

Molding of various widths used to trim window openings at the jambs. Also referred to as box post, and window surround.

• Lift

A handle or grip installed on the bottom rail of the lower sash of a double-hung window to make it easier to raise or lower the sash.

• Light (or Lite)

Glazing framed by lattice and/or sash in a window or door.

• Lintel

A horizontal member above a window opening that supports the structure above.

• Low-E Glass

A common term used to refer to glass that has low emissivity due to a film or metallic coating on the glass or suspended between the two lights of glass to restrict the passage of radiant heat.

• Mullion

A wood or metal part used to structurally join two window units.

• Rail

The top and bottom horizontal members of the framework of a window sash.

• Rough Opening

The framed opening in a wall into which a window unit is to be installed

• R-Value

Resistance to thermal transfer or heat flow. Higher R-value numbers indicate greater insulating value.

• Pane

A framed sheet of glass within a window.

• Sash

A single assembly of stiles and rails made into a frame for holding glass.

• Sash balance

A system of weight, cords and/or coiled springs which assist in raising double-hung sash and tend to keep the sash in any placed position by counterbalancing the weight of the sash.

• Sash cord

In double-hung windows, the rope or chain that attaches  the sash to the counter balance.

• Sash Lift

A protruding handle screwed to the inside bottom rail of the lower sash on a double-hung window.

• Sash lock

Generally, a cam-action type lock applied to the rails of a sliding window or at the open edges of a projecting window to pull the check rails tightly together or to seal the sash tightly to the frame, both for security and weathertightness.

• Sash weights

In older double-hung windows, the concealed cast-iron weights that are used to counterbalance the sash.

• Seat Board

A flat board cut to fit the contour of a bow or bay window and installed between the sills and the flat wall surface, providing a seat or shelf space.

• Shims

Wood wedges (often wood shingles) used to secure the window unit in the rough or masonry opening in a square, level and plumb position during and after installation.

• Sidelites

Narrow fixed units mulled or joined to bay or bow window units to give a more open appearance.

• Sill

The main horizontal member forming the bottom of the frame of a window.

• Single Glazing

Use of single panes of glass in a window. Not as energy-efficient as double glazing.

• Single-hung Window

A double-hung type of window in which the top sash is fixed or inoperable.

• Slider Window

Both sashes slide horizontally in a double-sliding window. Only one sash slides in a single-sliding window. Ventilation area can vary from a small crack to an opening of one-half the total glass area.

• Stile

The main vertical members of the framework of a sash.

• Stool

An interior trim piece on a window which extends the sill and acts as a narrow shelf.

• Stop Molding

A molding used to hold, position or separate window parts.

• Tempered Glass

Glass manufactured to withstand greater than normal forces on its surface. When it breaks, it shatters into small pieces to reduce hazard. Standard on all doors and large fixed windows.

• Transom

A small window that fits over the top of a door or window, primarily for additional light and aesthetic value.

• True Divided Lite

A term which refers to windows in which multiple individual panes of glass or lites are assembled in the sash.

• U-Factor

A measure of heat transmission through a wall or window. The lower the U-Factor, the better the insulating value.

• Vinyl

A plastic material used for cladding or entire window units.

• Weatherstripping

A material or device used to seal the openings, gaps or cracks of venting window units to prevent water and air infiltration.

• Windowpane divider

A short bar used to separate glass in a sash into multiple lights. Also called a muntin or grille.

IT COSTS YOU NOTHING TO FIND OUT

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  for a FREE, no obligation in-home evaluation and estimate. It never hurts to find out!