Sash Window Restoration: During a survey some sash windows or window sills can be found to be in poor condition and will need to be repaired or replaced. If a repair is not possible, a new like for like replacement will be made to the exact original specification. It is common for the window sills to rot and window tenon joints to become loose.
Where rot is found it will be removed back to solid timber. We use a two part epoxy resin based filler which is left to harden, sanded and primed. Any loose window tenon joints are cleaned out, glued, tightened with screws, filled, sanded and reprimed.
Broken and cracked glass is common with old windows and will be pointed out during the survey. Replacement glass comes in either clear float or patterned. Toughened or safety glass has to be used for any glazing under 800mm from floor level to comply with health and safety laws.
The Draught Proofing system is incorporated into the replacement parting beads, staff beads and bottom sash.
Once both sashes have been removed the replacement beads are fitted with a weather proof brush sealing all gaps around the window. The bottom sash is also routed on its mid and bottom rail in order to hold the brush ensuring a fully draught proof and smooth running sash window.
Many old sash windows have broken or badly fitted catches. The catch plays an important role from eliminating rattles to security. At Classic Sash Restoration we offer a wide range of new catches and sash lifts to suit your requirements. They come in many styles and finishes from screw catches to swing arm catches and from traditional polished brass to more modern chrome.
Security also plays an important role with any window. We offer the popular restrictors (restricts how far the window opens) and catches with built in locks.
About Sash Windows
A sash window or hung sash window is made of one or more movable panels, or “sashes”, that form a frame to hold panes of glass, which are often separated from other panes (or “lights”) by glazing bars, also known as muntins in the US (moulded strips of wood). Although any window with this style of glazing is technically a sash, the term is used almost exclusively to refer to windows where the glazed panels are opened by sliding vertically, or horizontally in a style known as a “Yorkshire light”, sliding sash, or sash and case (so called because the weights are concealed in a box case).
To facilitate operation, the weight of the glazed panel is usually balanced by a heavy steel, lead, or cast-iron sash weight or counter-weight concealed within the window frame. The sash weight is connected to the window by a braided cotton sash cord, or a chain, that runs over a pulley at the top of the frame, although spring balances are sometimes used. Repairing a broken cord requires disassembling parts of the window frame.
Sash windows may be fitted with simplex hinges, which allow the window to be locked into hinges on one side while the counterbalance on the other side is detached, allowing the window to be opened for escape or cleaning.
The term “sash windows” is used interchangeably with the term “box sash windows” in the United Kingdom, and frequently used to describe the same thing. Historically box sash windows are heavier and more stately in nature than modern sash windows, but both terms are used within the industry when referring to the same type of window.
The name “hung sash window”, which is more usual in the United States than in the United Kingdom, typically refers to a double-hung window with two sashes that can move up and down in the window frame. These windows are commonly found in older buildings in warmer climates, as they promote airflow and are easy to clean. A significant advantage of double-hung windows is that they provide efficient cooling of interiors during warm weather. Opening both the top and bottom of a sash window by equal amounts allows warm air at the top of the room to escape, thus drawing relatively cool air from outside into the room through the bottom opening. A double-hung window where the upper sash is smaller (shorter) than the lower is termed a cottage window.
A single-hung window has two sashes, but normally the top sash is fixed and only the bottom sash slides. Triple- and quadruple-hung windows are used for tall openings, common in New England churches.
Construction is usually of softwood, and these sashes were traditionally only single-glazed.
The glass in old windows can be the very early ‘plate’ or ‘broad’ glass to ‘crown’ or ‘cylinder’. Old glass is recognised by its imperfections (‘ream’) which result in optical distortion. Traditional cylinder glass is still made, but other sorts of antique glass are no longer available.
Modern double-glazed sash windows are available. These may have true muntins or “glazing bars”, or may imitate them by applying them to the surface of the glazing, giving the appearance of multiple small panes, whereas each sash consists of only one large double-glazed unit.