simply sash: Glossary↸
Glossary of Sash Window Terms
Back Lining - see Box Lining.
Bead - a woodworking term for a strip of wood with a moulded (often rounded) face. Used either decoratively or to reinforce the point where two straight edges meet. Collectively called beading.
See Parting Beads, Staff Beads.
Box Lining - a timber Outer Lining to either side of the window, between the stone surround and the window frame. This helps keep masonry dust out of the window frame and offers extra draught prevention.
Box Sash Window - see Sash Window.
Brush Strip - see Weatherpile.
Case - see Box.
Cheek - grooved vertical wooden sections either side of the window frame. They stand between the Sill and the top of the sash window Box and provide the Running Surfaces for the Sashes to slide against.
The cheeks have Pulleys through which the counterweighted sash Cords pass.
Cill - see Sill.
Cord - a corded rope used to connect a sliding Sash to a Counterweight. Each sash will be attached to cords on both sides of the window frame. Usually made of thick braided cotton. Sash cord comes in different gauges of thickness to suit the weight of the sash it needs to support.
Counterweight - a metal weight used to counterbalance the weight of a Sash and hold it in position at any height. A sash will have counterweights on either side, concealed in a Cavity and connected to the sash via Cords.
The weights are typically made from steel, iron or lead. Where space is an issue, lead weights may be the most appropriate, being denser for their size than other metals.
An alternative to traditional weights is a Spiral Balance.
When a sash needs Rebalancing, Add Weights may be used to adjust the counterweight.
Double Hung Window - see Sash Window.
Drifting - a Sash that isn't correctly counterbalanced and won't stay in place is said to drift. This causes the sash to move of its own accord, drifting open or closed, or slamming shut suddenly.
A drifting sash needs to be properly Rebalanced to restore the correct operation of the window.
Drip Groove - a narrow channel cut into the underside of an exterior window sill. Its purpose is to stop rainwater flowing back underneath the Sill where it can rot the sill or damage the joint with the outside wall.
- typically a hardwood beam that acts as the lower surface of a Sash Window. In some cases this sill may be stone rather than timber.
This is what the Lower Sash rests on when it is closed.
The exterior sill is sloped to allow rainwater to run off and will include a Drip Groove.
Glazing Bar - see Muntin.
Horns - where the vertical Stiles of a Sash extend beyond the height of the sash frame, the extra sections are called horns. Often ornately sculpted. A horned Upper Sash would have horns at the bottom, whilst a horned Lower Sash would have the horns at the top. These provide extra strength to the sash frames.
Hung Window - see Sash Window.
Inner Sill - this is a wooden sill on the inside of the window, jutting out a short way into the room.
Lite - an individual pane of glass in a window frame, often held by Muntin bars.
Make Weights - see Add Weights.
Meeting Rail - the bottom horizontal Rail of the Upper Sash and the top horizontal Rail of the Lower Sash are called the meeting rails, since they meet in the middle of a closed Sash Window. Also known as lock rails.
Muntin - a strip of wood that divides a window horizontally or vertically into smaller panes of glass (or Lites). Also known as muntin bars, glazing bars or sash bars. Georgian sash windows typically have 'six over six' panes, meaning each Sash has six individual panes of glass separated by muntin bars.
Parting Beads - long wooden strips that sit in a grooved channel in the Cheek and Box Head to separate the Lower and Upper Sashes so that they move freely and independently. These can be fitted with Weatherpile Carriers for reducing draughts.
Rail - a horizontal wooden piece that forms the top and bottom parts of a Sash frame.
Rebalancing - with painting and redecorating, over time a Sash can get heavier, causing it to become unbalanced and Drift, as its Counterweights no longer hold it correctly in place. When this happens the sash needs to be reweighed and rebalanced, with adjustments made to the counterweights, so that the sash operates properly again.
Rope - see Cord.
Router - a specialised carpentry power tool for cutting grooves or channels into wood. Pronounced "raow-ter".
Routing - the term for using a Router to cut a precisely sized channel into a piece of wood.
Sash - a sliding window frame, made from timber Rails and Stiles, containing panes of glass (or Lites). The sash frame is held within an outer wooden Box, along with a set of Cord ropes, Pulleys and Counterweights which support the heavy frame and enable it to move up and down.
Typically a Sash Window will consist of a pair of sashes: the Lower Sash and Upper Sash.
Also known as a sliding sash.
Sash Bar - see Muntin.
Sash Window - a traditional timber frame window that consists of moveable Sashes. Typical in period houses from the Georgian (including Regency), Victorian and Edwardian eras.
Also known as a box sash window, as well as a single or double hung sash window, depending on whether one or both of the sashes can be moved. The individual sashes are contained together within a Box or case.
Sill - a ledge or shelf that forms the lowest part of a window frame. Normally this term refers to the Exterior Sill but may also include an Inner Sill.
In the 1800s this was spelled "cill" and is sometimes still used in this way by the construction profession.
Spiral Balance - a tube containing a stainless steel rod and tension springs. This device replaces the traditional Counterweight, Cord and Pulley arrangement, freeing up room in the window Box. Also known as a Spring Balance.
Weatherpile - a flexible fin or brush shaped strip designed to seal gaps and keep out draughts, whilst allowing free movement of the sashes.
Weatherpile Carrier - see Weatherstrip.
Weatherstrip - a narrow plastic grooved channel into which a draught proofing Weatherpile can be fitted. Also known as a weatherpile carrier.
These can be fitted into the sash Rails, Parting and Staff Beads.
Whilst cheap stick-on adhesive weatherstrips are available, the long-lasting solution is to use a Router to create a permanent groove in the timber frame into which the weatherstrip sits.
Weights - see Counterweight.
Weight Cavity - The concealed space on each side of the window frame where the Counterweights hang. Also known as the weight pocket.
Weight Pocket - see Weight Cavity.
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