Argon Gas — Window Word of the Day

Argon GasArgon Gas:

An inert, colorless and odorless gas used to fill the airspace between the insulating glass panes which greatly increases the overall performance of the glass; Argon gas is less conducive to heat than air.

The glass panes are sealed to keep the gas from escaping to ensure a consistent interior temperature as well as overall energy efficiency.  This method works for all window frames and allows for unobstructed views and reliable insulation.

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Air Infiltration — Window Word of the Day

Air Infiltration
 Air Infiltration: The amount of air that passes between a sash and a frame; Measure in terms of cubic feet of air per minute per lineal foot of crack (margin).

Air infiltration is the major cause of heat loss or gain in a home. A reduction in air leaks will provide a more comfortable environment and improve energy efficiency in the home. Some ways to prevent air from leaking through windows include using caulking or weatherstripping and replacing glazing compounds. One of the best solutions for historic homes is to have failing windows restored; windows can also be replaced. Restored windows can last many years with proper maintenance.

If you’d like to explore how to correct air infiltration issues that may be occurring in your historic home, contact Versatile at  and a Client Services Specialist will be in touch.

Insulated Glass — Window Word of the Day

Insulated Glass

Insulated Glass (IG): Glazing comprised of two or more glass panes separated by a hermetically sealed airspace. Heat transmission through this type of glass may be as low as half that without such an air space. This space may or may not be filled with an inert gas, such as argon.

A hermetic seal makes the window airtight and minimizes the amount of warm (or cool) air that can pass through. This enables the mechanical ventilation system to recover the heat before discharging the air externally. These windows combine triple-pane insulated glazing with the airtight void between panes filled with argon or krypton gas to reduce thermal conductivity and increase R-value (insulation) efficiency.


Muntin Bar — Window Word of the Day

Muntin Bar

Muntin Bar: A short, lightweight bar that visually divides a window into “separate” panes.

Did you know: Until the middle of the 19th century, it was economically necessary to use smaller panes of glass, which were much more affordable to produce, and fabricate into a grid to make large windows and doors.


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Extension Jamb — Window Word of the Day

Extension Jamb

Extension Jamb: Lumber extending from a window or door frame to accommodate different wall thicknesses.

Why do you need an extension jamb? Since the energy crisis of the 1970s brought on the demand for thicker insulation, most contemporary houses are framed with 2×6 studs. Windows, though, are generally still configured for 2×4 walls, so the jambs have to be extended to bring the window flush with the drywall. Fine Homebuilding Magazine has an extremely detailed article on the process for properly measuring and installing jamb extensions- you can check it out here.

Frame — Window Word of the Day


Frame: The horizontal and vertical members of  a door or window unit which surround the sash, are used to secure the door or window unit into the rough opening and to the building, and/or to which the hinge and lock strike hardware are normally attached.

Frame components include:

Head Jamb: The top horizontal member

Side Jamb: the vertical side members

Sill: The bottom horizontal member

Did you know: The word “sash” is derived from the French word “chassis”  which means frame.


Legislating Frame Construction

Two pieces of English legislation affected the appearance of sash windows in London. They were imposed because exposed sash boxes were seen as a fire risk.

The 1709 Building Act stated that sash windows had to be recessed 4″ back from the outer brick-work or masonry. The 1774 Act required the sash windows box frame to be set behind the brickwork, so that only about an inch of the sash box was visible from the outside.

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Fingerjoint — Window Word of the Day


Fingerjoint: A series of interlocking fingers prcisely cut on the ends of two pieces of wood which mesh together with heat-based adhesive. It is stronger than a butt or lap joint, and often contributes to the aesthetics of the piece.

Alternate names include box-pin joint or box joint. It’s advantage is that it does not require nails or screws to create a very strong joint once glued. It can be much stronger than a dovetail joint because of the additional intersections that create additional surfaces for the glue to adhere to.

History of the Fingerjoint

The fingerjoint originated as the primary means of constructing quick but sturdy wooden boxes for bringing fruit and vegetables to market. These days it is used to creates a very traditional look for window and door construction.


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Casement — Window Word of the Day

Casement illustration

Casement: A window unit that swings open from one of its vertical edges. Casement windows are normally operated with either a casement lock and stay bar system (the traditional hardware) or a mechanical crank system with a concealed hinge.


This unusually long bank of casement windows was custom designed by Versatile Wood Products and features crank hardware with concealed hinges and integrated screens.


Here’s a look at how the operate from the interior of the space.

History of the Casement Window

(excerpted from the Stroud District Council’s Design Guide for Casement Windows in Preservation Districts. Check out the full guide here.)
Successor to the stone mullioned window, the traditional timber casement became the most common window type by the second half of the eighteenth century. Subdivided by glazing bars, joining together the small panes of glass, the earlier designs had the opening part of the window, the ‘casement’, made of iron with lead latticing to the glass


By around 1840, the beginning of the Victorian period, the frames and opening casements were made entirely of timber. Windows of 6-panes per casement were the most common pattern, but designs were occasionally elaborated by the use of Gothic arches or smaller panes, especially during the mid-nineteenth century.

Here’s an example of a gothic arch from the restoraton of the Sellwood Pioneer Church.

From then, though, glass technology improved and the number of panes per casement was reduced to two with one horizontal glazing bar. Traditional windows usually were no wider than about 450mm(18″) per casement.

Here are a few of the more unusual casements that Versatile Wood Products has created for clients:


Here’s a nifty arched casement.


This pair of matched casements were designed for the Timberline Lodge.


Did you know that casement windows are usually the most practical choice for fulfilling egress requirements in basement renovations? They can even be designed to exactly mimic the look of a home’s double hung windows to keep the exterior look consistent with the rest of the home.

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Check Rail — Window Word of the Day

Check Rail

Check Rail: The bottom rail of the top sash and the top rail of the bottom sash of a double hung window that meet horizontally in the center of the unit or the two vertical members of sash in a slider window that meet in the center. This is also sometimes called the meeting rail.

Check Rail

Did you know: Robert Hooke, the 17th century inventor of the double hung window was also the architect who rebuilt the famous London mental hospital, Bedlam (aka the Bethlehem Hospital, Moorfields) after the Great Fire of London?

Check Rail

Bedlam is Europe’s oldest extant psychiatric hospital and has operated as such, continuously, for over six hundred years. Hooke kept offices in the central cupola of the hospital until his death.

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Brick Mould — Window Word of the Day

Brick Mould

Brick mould: The part of the exterior of a window that is designed to cover the small gap between the frame and the exterior siding. It is typically made of wood, wood composite, aluminum or PVC and received its name because brick was once the most common exterior facade or facing.

Brick Mould

Traditionally, brick mould was made of wood, which insulates well and can be easily painted. Over time, however, exposure to water and sun can cause it to rot and crack. For maximum durability, it must be maintained with regular cleaning and painting.

Brick mould can also be aluminum-clad, which makes the surface extremely durable. It cannot be painted, but contemporary window manufacturers like Marvin provide a variety of profiles and colors to choose from and the result is a window that needs significantly less maintenance.

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