Window Sashes and Sash Windows

The terms ‘sash windows’ and ‘window sashes‘ are often thrown around a lot by window manufacturers, installers and even consumers, but the truth is that many consumers are usually not quite sure what the terms really mean. If you find yourself among that group, but have been afraid to ask what window sashes are for fear of looking stupid, here’s the quick tutorial you need so you can be “talking window” like a pro!

Bottom Line:
(Always collect 3 to 4 additional bids)

Bill — Site Editor

What Are Window Sashes?

Window sashes are a single panel of a window that consists of a frame within which a pane or panes of glass are inserted. Each sash can be further divided into ‘lights’ by muntins. Multiple movable parts are combined to form a sash window.

Sash Windows

These consist of a series of vertical or horizontal panels that form frames within which panes of glass are held (sashes). The panels are movable and can be moved vertically or horizontally to open the window. Glass panes within the sash are often separated by muntins (narrow divider strips) to form individual panes of glass, also known as ‘lights’.

When Did They First Come Into Use?

The original sash windows were first noted in the 1670’s in England. The window design is thought to have been invented by Robert Hooke, an English inventor and scientist.

Types Of Homes

Most homes incorporate some sort of sash window, either as a single or double hung. In fact, the most popular window style is a double hung window. They provide great ventilation and look very professional and classy.

How Do They Operate?

Most sash windows operate by sliding the two lift rails vertically up or down. Double hungs consist of two sashes that are both movable. Single hungs have only one movable sash. In applications that require much taller configurations, triple and even quadruple hung sash windows can be installed. However, these open horizontally, and are then referred to as sliding windows, but are not as common.

In hung sash windows, each lift rail slides in a separate vertical groove along the side jamb of the window. The side jambs contain weights to counteract and balance the weight of the window, which helps in the operation of moving the sash, as well as keeping it in place when open.

These weights are made of lead, heavy steel or cast iron and connect to the window sash by a cord and pulley system. The pulleys control the operation of opening and closing the sash. In some cases, spring balances are used instead of this system and compression weatherstripping can be used to keep a sash in place when open.

What Materials Can They Be Made Of?

Manufacturers make sash windows out of all the same materials as any other window material. So, these include vinyl, wood, aluminum, composite, and fiberglass. Vinyl is the overwhelmingly most popular material for windows in general. There are lots of reasons for this, but the principal one is that they are less expensive.

Benefits

The most significant benefit is how well they look, especially in older homes. Another advantage is that sash windows provide a good deal of ventilation. While they might not provide quite as much air flow as casements, they still are a great option.

With double sashes, the top and bottom sashes can both be opened, allowing cooler air to be drawn inside through the lower opening and warmer air to escape through the upper opening. Andersen Windows And Doors makes an excellent double hung series in the 400 model.

Problems

Since most older sash windows are wood, they can incur the same problems as other wood-clad options. Wood can swell or become distorted due to moisture and exposure to heat and sunlight. Additionally, they can rot due to weather, water and insects. Therefore, I always advise a high end vinyl window with a wood interior veneer.

The mechanisms that operate the sliding of the sashes up and down can also break, requiring repair or replacement. Wood sashes also require periodic painting, staining or sealing to protect the wood and to keep it looking good, and careless applications of these coatings can affect the overall operation.

Vinyl or uPVC sash windows do not have some of these issues due to the structure of the material. Still, some consumers will still encounter issues with the sliding mechanisms over time. Vinyl windows are much more energy efficient than wood and aluminum windows.

Replacement Windows Connect