A garage door is a large door on a Garage (house) that opens either manually or by an electric motor (a garage door opener). Garage doors are frequently large enough to accommodate automobiles and other vehicles. Small garage doors may be made in a single panel that tilts up and back across the garage ceiling. Larger doors are usually made in several jointed panels that roll up on tracks across the garage ceiling, or into a roll above the doorway. The operating mechanism is spring-loaded or counterbalanced to offset the weight of the door and reduce human or motor effort required to operate the door. Less commonly, some garage doors slide or swing horizontally. Doors are made of wood, metal, or fiberglass, and may be insulated to prevent heat loss. Warehouses, bus garages and Motive power depot have larger versions.
Single panel doors can also be installed with (one piece track type hardware) that folds the door back with a single horizontal track on each side (which is mounted at the top of the wood frame) and a roller, (mounted to the top of the door on each side. A hinge on each side that attaches to the bottom of each side of garage door. Using track hardware, a car can be parked much closer to the door, as the whole door, when in the open position, rests completely inside of the garage door header. Track type hardware has much less arc when raising and lowering the garage door as opposed jamb type hardware.
Garage doors can be made out of many materials, but steel, aluminum, wood, copper, glass, and Polyvinyl chloride (polyethylene) are the most popular materials. Some manufacturers incorporate foamed-in-place polyurethane insulation within the monolithic panel and sectional garage doors.
The side sliding sectional door[https://www.youtube.com/watch?v=ATLMwqBYlSY "Side Sliding garage Door"] PRIMO TIM 2014
In the UK (and other parts of the EU), 'insulated' roller garage doors are available, using an aluminium lathe filled with polyurethane foam for thermal and acoustic insulation.
In terms of thermal insulation, the roller door has a typical insulation value of 4.9 to 5.2. A sheet steel garage door has a typical insulation value of 6.1 to 6.4.
Application that need more thermal insulation typically use foam filled sectional garage door, which provide typical insulation values of 2.7 to 1.3.
A common material for a new garage door is steel sheet formed or stamped to look like a raised panel wooden door. Steel doors are available in uninsulated, insulated, and double skin steel. A design mimicking carriage house doors has become popular since early 2000s, and many manufacturers clad the exterior of a steel door with composite, vinyl boards, or other trim to give it the appearance of wood.
Some manufacturers advertise very high insulating values for some of their garage doors (R-15 to R-17), but it may be true for only for some central sections. The actual R-values – for the entire door – are often 1/2 or 1/3 of the advertised value.
A garage door with a broken spring, or the wrong strength spring, can fall. Because the effective mass of the door increases as the garage door sections transfer from the horizontal to vertical door tracks, a falling garage door accelerates rapidly. A free falling garage door can cause serious injury or death.
The sections and rollers on garage doors represent a major pinch hazard. Children should never be allowed near a moving garage door for this reason. On manually operated garage doors, handles should be installed vertically, to promote "vertical orientation of the hand".
Mechanical garage door openers can pull or push a garage door with enough force to injure or kill people and pets if they become trapped. All modern openers are equipped with “force settings” that make the door reverse if it encounters too much resistance while closing or opening. Any garage door opener sold in the United States after 1992 requires ''safety eyes''—sensors that prevent the door from closing if obstructed. Force settings should cause a door to stop or reverse on encountering more than approximately 20 lbs (9.07 kg) of resistance. Safety eyes should be installed a maximum of six inches above the ground. Many garage door injuries, and nearly all garage door related property damage, can be avoided by following these precautions.
Certain parts, especially springs, cables, bottom brackets, and spring anchor plates, are under extreme tension. Injuries can occur if parts under tension are removed.
Extension spring systems should always be restrained by a ''safety cable'' that runs through the middle of the spring, tying off to a solid point at the rear and front of the horizontal door track. Extension springs represent a hazard to bystanders when a spring, pulley, or cable breaks under tension. Metal parts from extension spring systems can suddenly be launched.