Vocab-lesson time! There’s not a huge amount of terminology used in conjunction with garage doors, but that which is used it rather important. So, break out the exercise books and learn the following!
Backroom: Relating to garages, the backroom is NOT the room where you go to play cards with the boys. It actually refers to the amount of space required to install a garage door, and is measured from the door to the back of the horizontal track.
Balance: the door’s ability to be raised and lowered easily, but not too easily that it shoots up or crashes down. This is affected by the opening mechanism and torsion springs and, if unbalanced, a door should be altered by a trained professional. As a guide, you should be able to open and close the door easily with one hand.
Bottom bracket: There are two bottom brackets, or corner brackets, on a garage door – one on the right, and one on the left. The lifting cables are attached to the bottom brackets on most sectional doors.
Cable drums: Cable drums are an important part of a tension spring system. As the garage door opens, the lifting cable winds around the grooves in the cable drum. It keeps the lifting cable in line, so it doesn’t get tangled.
Cable: The cable, or lifting cable, connects the bottom bracket to the counterbalance mechanism.
Clearances: You need to know your clearances for your garage door installation. That refers to how much backroom, headroom and sideroom, or the distance around the walls of the garage, is needed to efficiently install the door.
Cycle: One cycle of a garage door goes from when it’s fully closed, to fully open, and then back again to fully closed. Torsion spring doors are rated by how many cycles they’re supposed to safely complete in their lifetime, for example 25,000, 50,000 or 100,000 cycles.
Door frame: The door frame holds the garage door with two vertical pieces and a horizontal header, or top piece.
Door size: When specifying a door size, you give the width first, then the height.
Extension springs: Extension springs are one of the two types of spring systems used to carry the weight of a garage door as it lifts. They stretch on either side of the door, running from a pulley attached to the door, to the rear track hanger.
Flush design: A garage door with a flush design is flat, with no indentations or grooves.
Garage door opener: Garage door openers consist of all the hardware that combines to open and close a garage door. A garage door opener can be operated automatically by remote control.
Gauge: Gauge refers to the thickness of steel. The higher the number, the thinner the steel.
Hinges: Hinges are used to connect the sections of a garage door, allowing the door to bend as it runs up the vertical track and onto the horizontal track.
Insulation: The insulation in a garage door can be made of polystyrene foam or polyurethane filler. Polyurethane insulates better than polystyrene, but polystyrene lasts longer.
Jamb seal: The jamb seal is the weather-stripping that runs around the door jamb, stopping drafts and rain from entering the garage.
Lift-handle: A life handle is sometimes installed on a garage door for use if manual operation is required.
Lites: Lites are the industry’s word for glass or clear plastic windows in a frame. Some lites are double-glazed for insulation.
Low headroom: If your garage ceiling is lower than normal, you may need special low-headroom track hardware accessories.
Opening size: The opening size refers to the distance between the walls and the doorjambs in a garage door opening.
Overhead garage door: An overhead garage door is one that’s built in hinged sections, allowing it to travel up and down tracks as it opens and closes.
R-value: the amount of insulation offered by a garage door. An average door might require an R-value of around 4 or 5; in colder climates 6 or 7 is also appropriate. If you use your garage for work, a higher R-value is always preferable.
Sectional doors: Sectional doors are just that – doors made up of sections hinged together, thus allowing it to bend around the track as it opens and closes.
Stop molding: The stop molding is the wooden or plastic piece that’s attached to the outside of the door jamb, to seal out weather and light.
Track: The track is the part that holds and guides the roller assembly. It runs vertically to the top of the garage door, then horizontally parallel to the ceiling.
Windload: Windload refers to the force of the wind as it hits a garage door in the closed position. In hurricane or high-wind areas, doors are required to carry up to 110mph windload resistance.
For more info see this FAQ