All about Sash Windows

The two sashes slide over one another vertically, controlled by a cords which run over pulleys and counterbalanced with metal weights.

The counterbalancing makes them feel lighter and easier to open and close. In all sash windows, the bottom sash can be slid upwards. In double-hung sashes, the top sash can also be slid downwards.

The sashes can be clasped together in a closed position using a sash fastener situated on the top of the bottom sash. There’s usually also a stop lock for additional security, which prevents the window from travelling too far upwards and bottom sash lifts to aid raising the lower sash.

It’s thought that sash windows were invented in England by architect Robert Hooke. They offer a very large area of opening and part of their design may have been to allow a quick and easy escape route in the event of fire – something very much on the minds of building designers in London, particularly after the Great Fire of 1666.

The distinctive Georgian style of 6-panelled sashes, normally arranged in two rows of three panes, came about partly because of the technical difficulty of making large single panes of glass. Later, as glass became stronger and cheaper, larger single panes could be used.

As beautiful as they are, sash windows suffer from some common problems, especially older or original ones.

They can jam when their wooden boxes expand or are painted over or when dirt builds up between the sashes and the surrounds. The opposite problem occurs when the sashes become loose within their boxes causing drafts, rattling and uneven running.

The window frames and sills can become rotten or overpainted.

The internal cords can fray and break or become dirty and unsightly. And they can allow cold air or even rainwater in.

All of these problems can be fixed by sash window refurbishment, which involves removing the window from its box, stripping, sanding, and repainting the boxes and sashes, replacing the cords, cleaning the windows, repairing the joints, and refitting the windows.

Sash window restoration is a specialist job, which here at SashWise we have a highly skilled team of craftsmen with over 25 years of experience between them, that can restore sash windows to their former glory.