Understanding Basic Replacement Window Terminology

Replacement WindowSome of the main window terms you will come across are shown below, however you may also want to refer to our FAQ & Glossary section which gives a far more detailed list of the main terminologies you are likely to face.

The main elements to any general window which you may come across when installing windows will include the head, the jamb, the frame, the glazing, the window panes, a sash, the window sill and finally the muntin bars.

The Window Head

The window “head” is actually referring to the upper most part of the window which sits across and above all other parts. The head represents the very top of the overall window piece and will usually sit around the same height as the lintel.

On many homes the window head is often the most decorative and are available in many different styles and types to fit with the look you are trying to achieve for your home. These decorative heads are usually fitted to certain windows such as windows fitted to bays or to particular outcrops on the building.

The Window Jamb

The window jamb act as one of the structural support elements for your window and are fitted inside of the actual window frame. The window can have jambs at the head of the window, known as head jambs and at the sides of the window, known as side jambs.

Although jambs are not always required you will find that they are common to most window installations these days and having them will add to the overall structural integrity of your window installations.

The material from which window jambs are made can vary depending on the window itself. The most common materials will include wood, vinyl, plastic and metal.

If you find that you’re windows are leaking or that gaps are starting to appear around the edges of the actual window installation, replacing the window may not be the first option to consider. Examining the window jambs closely may sometimes reveal that the problem is with the jamb and not with the window itself, replacing the jamb is far less costly than replacing the whole window. It’s always a good idea to look at hiring or seeking the advice of a qualified window contractor for help with this aspect. Our window contractor guides section gives advice for hiring contractors.

The Window Frame

The window frame is one of the parts of the windows which 99% of people will know, it’s the out portion of the window inside which the glazing sits and other elements of the window, such as sashes, move.

The Window Glazing Or Panes

The glazing of any window is the glass within the window, also known as the window panes. These panes are fitted into the window frame using various methods. Glazing is also used as the term to refer to the process of adding material to panes of glass.

The Window Sash

The sash on any window refers to the section of the window which moves, windows with a sash are referred to as sash windows. The sash is usually made up of a simple frame and either multiple small panes of glass or larger single panes of glass. The sash can then be easily inserted into the window casement, usually by a set of metal runners which allow the window sash to move up and down.

Sash windows can consist of two or more movable sash elements or a single movable sash element. Windows with only one movable sash are known as single hung sash windows and ones with upper and lower movable sash elements are known as double hung sash windows.

Some larger sash window configurations allow for multiple movable sashes, these are often installed into much larger commercial or public buildings, they’re not usually seen in domestic homes.

The Window Sill

Just like the window frame, the window sill is one of those parts to a window which people don’t usually struggle with recognising. The sill is the lower part of the window which sits below the window frame and usually juts out from the wall.

The Muntin Bars

The muntin bars on a window usually divide one large window into smaller individual panes and hold them in the window frame. The muntins are seen as the dividers which run horizontally and vertically on the window.

Traditionally the muntins did actually hold the smaller panes of glass in place within the one window frame, however that’s not always the case with modern windows of today. Muntins within modern windows are often used purely as a decorative element which provide no structural support whatsoever. These modern windows are made from large panes of glass and the muntins are placed directly onto the glass rather than physically dividing it.

Muntins can be made from a number of different materials including plastic, lead, metal or aluminum. The more modern muntins used purely for decorative purposes are usually constructed from plastic or aluminum.

For an overview of some of the other terms you may come across when replacing your windows visit our replacement windows glossary of terms.

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