• Air and Water Infiltration

    The amount of air and water that passes between the window sash and frame.

    Air space

    The space between the panes of glass of a sealed unit

    Air space

    The space between the panes of glass of a sealed unit

    Argon Gas

    An odourless, colourless, tasteless, non-toxic gas, six times denser than air. It is used to replace air between the glass panes to reduce thermal transfer.


    The center member of a double door, which is attached to the fixed or inactive door panel.

    Awning Window

    Awning Vinyl Windows-hinged window that can be cranked open from the bottom, swinging outward for ventilation. The glass faces downward when the window is fully opened. Awnings are great for bathrooms and other spaces that require privacy. They can be opened for ventilation even when it is raining (due to the angle of the window).

  • Bay Window

    Bay Windows consist of of 3 windows in an angled shape, with the center window generally much larger than the other two

    Bow Window

    Bow Windows consist of of 4 to 6 windows in an arch shape, where all the windows are the same size.


    A rubber material that seals the glass to the spacer, creating an airtight and water-tight IG unit.

  • Cam Lock and Keeper

    The mechanism that pulls the sash together when placed in the locked position.


    Cosmetic covering, usually found on the exterior of the window or door.

    Casement Window

    These windows open outward via a hinge mechanism. They can open on the left or right side, and are perfect for spaces that need sufficient ventilation. They are often installed in hard to reach spaces, given the ease of which they can be opened by a crank handle.


    A mastic compound for filling joints and sealing cracks to prevent air and water infiltration.


    Transmission of energy (heat and cold)


    Heat transfer by currents that flow from a warm surface to a cold surface.

  • Deadbolt

    The locking mechanism that is installed on entry doors. It features a bolt that locks into place within the frame. Deadbolts provide greater security than standard door locks.

    Door Jamb

    The part of a door frame which surrounds the edges of the slab.

    Door Sweep

    Weather-stripping structure that is installed at the bottom of the slab to prevent air and water from entering the home.

    Double Insulated Glass Unit

    Two glass panels separated by an air space within an opening to improve insulation against heat transfer or sound transmission. The air between the glass panels are thoroughly dried, the space is sealed airtight and filled with argon gas, eliminating possible condensation.

    Double Hung Window

    Double Hung Windows open on the top and bottom. You can open the bottom sash when you need to cool a space and the top when you want to let vent warm air out.


    A material that has two or more levels of flexibility. An example is the weather stripping used between the frame and sash of a casement window.

  • Easy Clean Glass

    A specialty option that can be applied to the glaze; it refers to the coating that helps prevent moisture and grime buildup. Rain that comes into contact with these windows will be sheeted off; this option is recommended for high up or hard to reach units.

    End Vent Slider

    Window that features a fixed center sash with two sliding outer sashes. The sliding panes can be tilted inward for cleaning purposes.


    ENERGY STAR® is an independent government program with a standard set of guidelines to recognize the energy efficiency of various products.

    Entry Door

    Also known as a “front” or “main” entrance door.

  • Fiberglass Doors

    These doors are very durable and are a recommended choice for most households. They have the beauty of hardwood, but are not subject to dents, cracks or splitting. The paneling designs on fiberglass doors can be custom-tailored for a unique finish.

    Fixed Panel

    Fixed Panel Window or a Picture Window are windows that do not open. Picture windows can be installed anywhere; they provide maximum energy-efficiency due to the lack of an opening system.


    The enclosure in which the window sash or door panels are mounted. Refers to the part the sash fits into (head, jambs and sill).

    Full Screen

    A screen which covers the entire opening of a window.

  • Gas Filled Units

    Insulating glass units with a gas other than air (usually an inert gas such as argon) in the airspace between the panes.

    Gas Fillings

    Refers to the type of gas that is present between the panes of glass. Argon and Krypton fillings are often used, as they work to slow down the heat transfer inside the glass. This increases the energy-efficiency of the window better than windows that contain air.


    Double pane unit of glass sits inside the sash or frame.


    The process of sealing the glass to the sash. This can refer to the number of panes that are in the window.


    Horizontal or vertical bars installed between the glass panes to create a decorative effect.

  • Half Screen

    A screen which does not cover the entire opening of a window. Most commonly used on the bottom half of a single hung unit.


    The horizontal top portion of a window or door frame.


    A movable joint allowing a window or door to swing open.

    Horizontal Slider

    A window with movable panes that slide horizontally.

  • Infiltration

    Leakage of air or water into or outside the home, usually through cracks around the sash or the window frame.

    Inner Sash

    The wider sash, closest to the inside of your home.


    A design feature which enables sashes to engage one another when closed.

  • Lift Handle

    A handhold for raising and lowering the sash. (Double hung or slider)


    A horizontal member above a window or door opening that supports the structure above.


    A unit of glass in a window or door.

    Low E Glass

    Glass with a transparent metallic oxide coating applied onto a glass surface. The coating allows short-wave energy to pass through but reflects long-wave infrared energy which improves the U-value.

  • Main Frame

    Material used to build window frame.

    Multi-Air Chambers

    Small honeycomb spaces within the sash and frame which help insulate and strengthen the window.

    Masonry Opening

    The space in a masonry wall left open for windows or doors.

    Mechanically Fastened Frame

    Refers to window and door frames fastened with screws.

    Meeting Rail

    (in a double-hung or double slider window) the rail of each sash that meets a rail of the other, when the window is closed.


    Fabric made of fiberglass used in the making of screens.

    Multi-Point Locking

    A term used for locking hardware that engages a window sash to the frame at multiple locations with a single throw of an operator.

  • Night Tab

    Small tabs fixed on the outer sash. These tabs can be extended to prevent the window being opened fully from the outside.

  • Obscure Glass

    Glass that has been made translucent instead of transparent.

    Operable Window

    A window that can be operated for ventilation.


    Crank-operated device for opening and closing casement windows.

  • Pane

    One of the divisions of a window consisting of a single plate of glass.


    A major component of a sliding glass door, consisting of a lite of glass in a frame installed within the main (or outer) frame of the door. A panel may be sliding or fixed.

    Patio Door

    Door that slides open and close on adjustable tandem rollers. Available in 2, 3 and 4 section configurations.

    Picture Window

    Picture Window A window that does not open (no moveable sash).

    Privacy Doors

    These doors feature special glass designs that prevent people from looking through them. They work great as entry doors, as the bevel designs are attractive and functional.

    Pull Handle

    A handhold for sliding the sash back and forth. Handle implies that the handhold is not continuous across the sash.

  • Quarter Round Window

    Quarter Round Window Stationary or operating window shaped as a quarter circle.

  • R-Value

    The resistance that a material has to heat flow. The higher the R-value, the greater the resistance. The heat loss by windows is expressed with U-values, or U-factors. U-values are the mathematical inverse of R-values.


    Wave energy transmitted directly from one object to another through the atmosphere or through transparent or translucent materials. The energy radiated is either transmitted, absorbed, reflected or a combination of all three.

    Replacement Window

    Replacement Window A window that is designed for and subsequently installed after the removal of all or part of a previously-installed window.


    Adding or replacing items not provided at the time of original construction. Typical retrofit products are replacement doors and windows, insulation, storm windows, caulking, weather-stripping, vents, and landscaping.


    That part of the edge of a door or window jamb not covered by the casing.

    Rough Opening

    The framed opening in a wall into which a window or door unit is to be installed.

  • Safety Glass

    A strengthened or reinforced glass that is less subject to breakage.


    The components that hold the window glass in place inside the frame.

    Sash Stop

    A molding that stops the sashes from rubbing together at the interlock.


    Woven mesh of metal, plastic, or fiberglass stretched over a window opening to permit air to pass through, but not insects.


    A compressible plastic material used to seal any opening or junction of two parts, such as between the glass and its sash, commonly made of silicone, butyl tape or polysulfide.

    Side Lite

    A tall, narrow, fixed or operating sash on either or both sides of a door to light an entryway or vestibule.


    The horizontal section located at the bottom of the frame.

    Single Hung

    A window in which one sash slides vertically and the other sash is fixed. Generally, the bottom sash is the operable one.


    Slab doors can be equipped with textures or left as a single surface; you can also choose to have glass inserts installed (for certain interior doors)

    Sloped Sill

    The sill of the window that has a downward slope to the outside, to assist in excessive rainwater runoff.


    A strip of stainless steel or superspacer metal separating and holding panes of glass in a window.

    Square Foot

    A unit of measure for designating an area of one foot by one foot. Derived from width (in inches) x height (in inches) divided by 144 = area in square feet.


    Attack on the glass surface by water or other solutions.


    The upright of a window frame in which the sash pullys are installed and along which the sash jambs.

  • Thermal Expansion

    A change in dimension of a material as a result of a temperature change.

    Tilt Latch

    A mechanism that unlocks the sash and allows it to tilt in for cleaning.

    Tilt-In Sash

    A sash that can be tilted to the interior for cleaning.

    Tinted Glass

    Glass with a material added to give the glass a light and/or heat reducing capability and colour.

    True Divided Lite

    A term commonly used to describe the arrangement of grills in a single sealed unit giving the effect of divided lites (individual panes of glass in a single unit).

  • U-Value

    Amount of heat transferred through a material. The lower the U-value, the slower the rate of heat flow and the better the insulating quality.

    Ultra Violet

    Type of radiation with wavelengths shorter than those of visible light and longer than those of X-rays. Causes sunburn, fading and breakdown of fabric, wood, furniture and other exposed surfaces.

  • Vent

    The operating portion of a window that swings or projects in or out.

    Venting Unit

    A window or door unit that opens or operates.


    Vinyl is a generic term for modified PVC (Polyvinyl Chloride).

  • Warm Edge Spacer

    Use of a non-conductive edge spacer in insulating glass units instead of the conventional aluminum (conductive) edge spacer. “Warm Edge” spacers may be made of butyl, silicone foam or other non-metallic materials and sealants.

    Weather Stripping

    Material used to form a weather-resistant seal around operable sash to prevent air and water infiltration. These are foam compression pieces that are installed on both sides of the door inside the frame; this is used to seal air gaps and maximize energy-efficiency.

    Weep Holes

    A drainage system consisting of vented slots at the bottom of a frame.

    Window Frame

    The fixed frame of a window which holds the sash as well as the operating hardware for the window.

    Window Hardware

    Various devices and mechanisms for the window including cords, chains, fasteners and locks, hinges and pivots, lifts and pulls, pulleys, sash weights, sash balances etc.

    Window Style

    The description of the way a window operates; example hung, sliders, casements etc.

Request Information



How long will the new windows and doors last?

They will last the lifetime of your home. With our hands down best in the business warranty we stand behind our promise to ensure you peace of mind. No fine print and fully transferable to... Read More

View All

We were satisfied with the installation work area was cleaned up and installers were friendly and knowledgable for the installation the only issue that we had was the finish causing on the outside... Read More

-John Leonard and Linda T
View All

Do You Need Gutter Protection?

We can’t control the weather, and when it rains heavily, it’s hard to control where the water goes. If the water gets into the wrong places, it can cause a lot of damage to our… Read More

View All


Click for the BBB Business Review of this Windows in Thorold ON
Sign up to receive special offers and promotions from Landmark

© 2018 Windows & Doors Installation Company - All Rights Reserved.