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A — D  |  E — H  |  I — M  |  N — R  |  S — T  |  U — Z

A — D

Arch Tops — Doors that have arched windows or other arched exterior materials that fill an arched or square doorway and give the appearance of a curved-top door. The actual framework of the door is square but can only be seen from inside the garage.

Astragal — A type of weather stripping. Most astragals are constructed of a U-shaped piece of vinyl that fits along the bottom of a garage door so the door has a seal when closed, even when the garage floor is not exactly level or flat. This seal prevents the elements from getting into the garage.

Bow or Bowing — Refers to the tendency of wood doors to bend in or out due to temperature changes and the pull of gravity on the door when it is hanging in the open position. Bowing can be reduced with proper reinforcement of the door, such as the struts that support doors. Also tightening of nuts on an annual basis can help reduce bowing.

Brackets — Metal pieces attached at the corners of a garage door to hold the roller and provide a point of lift for the cable. The top brackets are adjustable so the garage door has a tight fit when closed.

Cable Drum — A grooved drum that is fitted onto the torsion spring shaft and around which the lifting cable winds as the door is opened.

Cable — Heavy-duty multi-strand aircraft-grade wire used to attach the door to the spring system.

Clear Rails — An excellent grade of lumber, which allows small, tight knots but is generally free of knots and has no finger joints. Clear rails are mostly used on stain grade doors.

Cross Buck — Boards placed on the door to form an X. A single diagonal board is known as a half-buck. Cross bucks give a country flavor to a door’s design.

Cross Buck
Half Buck

Cross Buck


Door Stop — Wood or vinyl piece of trim that is nailed to the side and top surface of the jamb.

Double Door or Doublewide Door — Refers to 12 foot or wider garage doors, usually for two-car garages.

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E — H

False Post — A piece of trim applied to a double door to make it look like two single doors. The “post” goes up when the door goes up. More common on carriage style wood doors.

Finger Joint — A joining of shorter pieces of lumber to create one longer piece by cutting joints in the pieces, fitting them together and securing them with a waterproof adhesive. Finger joints are commonly accepted as an economical way to create one long piece of wood use for paint grade doors.

Flat Panel Door — Traditional-looking garage door from the 1940s to 1960s. The rail-and-stile framework looks like rows of picture frames with flat or recessed panels.

Flush Door — No raised panels are visible from outside. The door is a flat surface.

Foam Core — Polyurethane insulation. Spray in type.

Header — Support lumber running across the top of the garage door opening.

Headroom — Measurement from the top of the door opening upwards to the lowest obstruction on the ceiling of the garage. This measurement is used to determine clearance all the way back to the end of the horizontal track. Usually 12” to 18” is considered the minimum headroom for a normal 15” track. Clearance of less than 12” (low headroom) requires special tracking and advance planning.

Hinges — Hardware that connects the different sections of the garage door allowing it to function as a single door but still “break” in sections as the door opens. Hinges are found on the end stiles and center stiles at the meeting rails.

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I — M

Jamb — Upright framing on each side of the garage door opening. The door stop is nailed to the side surface within.

Keyless Entry — Keypad located on the exterior of a garage that operates the garage door when the proper code is entered, usually wireless.

Lites — Individual window panes. The pattern of lights or panes in a garage door can match the windows in the home, providing a complementary architectural statement.

MDO Plywood — Medium Density Overlay Plywood an exterior grade layered wood product.

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N — R

Paint Grade — Description for garage doors that will be primed and painted and not stained. Paint grade doors usually have finger jointed rails.

Panel — Term used to define the design of a garage door from side to side, i.e. a four panel door would indicate a door visually separated into four areas across. Also, a term used to denote construction method of garage door that has a number of individual panel sections where the framework is visible at the surface of the door. Refer to “section.”

Radius — Curve of the horizontal track that allows the door to go from vertical to horizontal (and vice versa) when moving. The curve is measured in inches and is determined by the headroom available.

Radius (Curve Top) — Contour of an opening to which the door is constructed to match.

Rail and Stile Framework — Horizontal and vertical framing pieces that shape and support a panel door, giving a “picture frame” look. Panel Doors can either be flat or raised panel. See flat panel door and raised panel door.

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S — T

Sag — When the rails are not level or straight, the middle of a door is lower than the ends. Sag is often caused by improper or lack of maintenance.

Scribe — To cut the bottom rail of a wood garage door, so that it can follow an irregular or uneven floor up to 1 ½”. Note: See “Trailer” for floors that are out-of-level more than 1 ½”.

Section — Row of framework and panels when stacked on top of one another create the entire garage door. Usually a door is split into 4 sections but may have 3 or 5 sections. Sections do not necessarily have to be the same height, but must fall within certain design parameters.

Slide Lock — Lock mounted on the interior of the door that slides into the track.

Side Room — Space on each side of the door to the nearest obstruction within the garage. Usually 4” is needed for easy track installation.

Stain Grade — Description of garage doors that will be stained and not primed and painted. Usually made from high quality wood (Hemlock, Cedar, or Mahogany) and costing more than Paint Grade.

Stiles — Vertical pieces of framing separating and supporting panels in a door.

Struts — U-shaped metal reinforcements attached to the inside of the door to add strength and rigidity, minimizing sag, and bow.

Torsion Springs — Springs mounted on a shaft above the door opening that counter balance the weight of the garage door. The coiled springs turns the shaft. This movement raises and lowers the garage door by turning the cable drum, which in turn winds and unwinds the cable attached to the garage door. While torsion springs are generally smoother and safer in operation than other spring systems, these complex mechanisms require professional installation.

Track — Path for the rollers, usually consisting of 2 vertical and 2 horizontal pieces. One end of the horizontal piece is curved into the radius. When closed, the door is resting in the vertical track. When open, the door is suspended from the horizontal track.

Trailer — A piece of rail that is scribed to fit your out-of-level floor and attached with hinges to the bottom of the door. Mostly used on wood doors.

True Divided Lights — Layout of windows that divides a window section into small individual panes of glass set in framing. This construction method is stronger and more authentic than grid overlays or routed out windows.

U — Z

V-Groove — The “V” created between 2 tongue-and-groove boards when they are fit tightly together. V-groove can also be routed into plywood to give the appearance of a tongue and groove boards.

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