Jargon buster

Let’s be honest, there’s quite a lot of jargon used in the windows world so we thought you’d appreciate a guide which provides you with information on a lot of the terms used and referred to by window and door specialists.

This guide just explains the terms so if you need detailed explanations or advice, then speak to us for more information.

Architrave The decorative wooden milled frames around the sash window which cover the sash window box. They are NOT part of the sash box but fitted after the window is fitted. They cover typically half the box and part of the wall around the box in order to create a seamless “frame” look.

Astragal Bars Decorated sculptured bars that give a window the illusion it has individual panes of glass. These are positioned on both the inside and outside of the glass with a spacer bar inside the sealed unit.

Bead Small convex moulding.

Casement Window A casement is a window that is attached to its frame by one or more hinges. The frame is fitted inside an opening or aperture from brick to brick, unlike a sliding sash window there is no recess or rebate required for a casement window. Casement windows are usually fitted from the outside, where as sliding sash windows are usually fitted from the inside.

Cavity Wall Usual construction for external walls comprising an inner and outer leaf with a space between for insulation.

Cords and Weights Sash windows which rely on a basic pulley system with weights to counter balance the weight of the window sashes when you open them. Each sash, top and bottom is hung on a cord or rope which runs along the edge of the inner window.

‘D’ Handles ‘D’ handles are fitted to the outside sash to assist opening and closing.

Flush Door or Window Door or window with completely flat faces.

Georgian Bars Internal decorative bars that create a Georgian effect. Available in widths of 18mm and 25mm.

Horns Placed on the outside or inside of the sash as an original feature. They are not fitted as standard and therefore must be specified with your order.

Jamb The side of an opening in a wall for a door or window.

Knots Naturally occurring circles in timber caused by the growth of a branch.

Knotting Varnish to stabilise knots in wood.

Lintel Concrete or steel beam over opening to the support wall above.

Lipped Door or Window Door with a lip which sits proud of the frame

Parting beads Parting beads are used to separate each set of sliding sashes. They are found in the middle of a sash box, and are fitted vertically the from top of a sash box to the bottom.

Plaster Applied wall finish.

Plasterboard Prefabricated sheets of plaster for walls and ceilings.

Pole Rings Fitted on the inside to the top sash to assist with opening and closing. Also known as finger pulls or pole eyes, they are fitted as standard to all our sash windows.

Rail Horizontal member in door or fence.

Recess/Rebate and Reveal For box sash windows the width of the external wall opening will be smaller than the internal wall opening. This allows the box sash to sit in the recess, also known as a rebate.

This guide diagram explains the terms in more detail:

Relieving Arch An arch constructed above a lintel or beam to take the weight of the wall above.

Render External sand-cement coating for walls.

Sash Not to be confused with a Sash window which is the shortened name for a sliding sash window. The sash is the name given to the section of a window that opens.

Sash Lifts An ‘r’ shaped handle positioned internally at the bottom of the sash to lift the window up. These are fitted as standard to all our sash windows.

Sash Stops A small space of wood used to restrict the sash from opening fully and bashing the frame, causing damage. Also known as limit stops or a frame stop. All our sash windows are fitted with sash stops as standard.

Sliding sash window Sometimes shortened to sash window. The sash is the name given to the section of a window that opens, when two sashes a combined into a box frame with the ability to slide vertically; this is called a sliding sash window.

A shelf at the bottom of a window inside a room or a horizontal piece along the outside lower member of a window that throws water clear of the window.

Skim Finishing coat of plaster.

Skirting Horizontal board at junction between floor and wall.

Spring or Spiral Spring loaded sashes are, as their name already points out, not hung but affixed to a spring. What is used today is actually a spiral type slider spring mount contained within a tube, which holds the sashes in place. The springs are affixed to the sashes on one end and to the window frame at the other.

Staff Beads Staff beads are the long wooden trims that keep the sashes in place. There are four on the interior on the sash box; one along the top, one along the bottom, and two down each side.

Travel Restrictors A small device used to restrict the opening of the sash to 100mm, sometimes required to meet current building regulations. Available in polished chrome, satin chrome and brass.

Trickle Vents Predominantly placed in the top of a window and used to allow ventilation. Trickle vents are not fitted as standard but maybe required depending on building regulations. Trickle vents are small passive ventilation openings which can be built into windows to allow additional airflow in poorly ventilated rooms.

‘U’ Value U-value is a measurement of the rate of heat loss from the warm inside of the house through the window/door to the colder outside. The lower the U-value, the smaller the loss of heat, i.e. better energy performance.

Warm Edge Spacer A more thermally efficient, and aesthetically pleasing, glazing spacer bar is used around at edge of a sealed double or triple glazed unit. It separates the two panes of glass by a specific gap and it’s what you see when you look inside your double glazed unit.