By 
As an expert door witness, I am called many times a year to evaluate garage door injuries. Garage doors come in many shapes and sizes. Its functions range from basic security of an area to cosmetic concealment. Most doors can be divided into a few basic styles or categories. Typical modern garage doors for residential applications tend to be efficient of the overhead sectional variety. That style of door comes in many configurations, materials, insulation levels, and a wide range of appearance possibilities. They are available as a prefabricated kit or built as a custom design to complement any building’s décor. Commercial warehouse type facilities often impose higher security requirements. A good choice for this type of security door is the “roll-up” style which resembles a type of roll-top desk door. This door can be made from a variety of materials that can be as strong as the adjacent walls, making forced entry through this opening very difficult. Other common commercial installations include sectional or single panel lightweight aluminum doors. These doors function more to close off an already secured area than to ensure the security of a point.
In the past, the biggest concern when operating an overhead garage door was the potential hazards associated with the springs used to balance the weight of the door. Garage door installations prior to the mid-1960’s generally relied on a pair of stretched (tensioned) springs to aid the operation of the garage door’s pivot hinges. These springs were charged (stressed) when the door moved to the closed position. The discharge (release) of the stored spring energy occurred when the door was opened to the top horizontal position. One of the most dangerous aspects of these spring systems was that after a period of time, often without any type of maintenance or inspection, the attachment points of these springs would rust or become weak. This weakening of the springs or attachment points would often lead to an unintentional explosive failure that would throw the broken spring components across the garage, embedding the spring or steel components in the garage walls, cars, or other items in the path of the spring. journey. Unfortunately, sometimes people found themselves in the path of these explosive events. Since these springs failed, as a safety measure some manufacturers devised a “caging” system for the springs. These cages were fitted to the stretched springs in an attempt to capture the parts that would come loose if a failure were to occur. While these caging devices were helpful, they were not completely effective. Some of these spring loaded devices are still in use today. Whenever this condition exists or the quality of shop components is questionable, a qualified professional service technician should be consulted.
In response to the inherently dangerous problems with older style garage springs noted above, a newer and safer system for opening your overhead garage door has been created. The idea was to transfer the load or weight of the door via a cable and pulley system to a vertical bar now fitted with a (twisted) torsion spring. This type of spring is installed with special hardware and bolted to a fixed plate at one end, while the entire spring is installed around a horizontal tube. This load balancing device is typically installed directly above the head of the garage opening. Using appropriate cables, connectors, and pulleys, the weight of the garage door is transferred to the torsion spring system. The difference between the old style stretched spring and the newer torsion spring is the way the spring energy is stored. With the old-style stretched spring, energy is stored and released by either pulling the spring or returning it to its unstretched condition. With one type of torsion spring, energy is imparted or removed by turning the spring clockwise or counterclockwise, depending on the direction of use. With professional installation, the full load of the torsion spring is controlled by the garage installer and is determined by the weight and size of the garage door being operated. When this type of torsion spring fails, it remains attached and intact at the horizontal control rod location where it was mounted. I have not heard of or seen any torsion springs fly across a garage, creating injuries from faulty components like stretched out old style garage door springs. This is not to say that injuries have not occurred with the torsion style spring. Installation of this type of spring is generally safe when left to a trained garage door installation professional. Serious and serious injuries have occurred when untrained and unqualified persons have attempted to install or repair this type of spring. In most installations, a warning label is left next to the torsion spring when the garage door is installed. This label warns of the danger associated with the stored energy of this spring and alerts untrained persons not to attempt to repair, adjust, or even touch the spring and associated hardware. When the label to be attached to this spring is damaged, removed, or tampered with, it is important to immediately reattach a new warning label to show the dangers of tensioning this spring.
Garage doors can be operated manually (by hand), as well as automatically (by power assisted motor). In both cases, the proper operation of the garage door is determined by the proper balance of the weight of the garage door, springs, and related hardware components. An assisted automatic motor cannot overcome a poorly balanced garage door. The weight of all garage doors is often misleading. Due to the fact that a properly functioning door appears easy to open and close, many users do not realize the total combined weight until the springs stop assisting the door in its operation. In all cases, regardless of the type of garage door, the entire system of hinges, guide, fittings and door opener work as a team. Misalignment, displacement or binding problems can cause problems in the operation of a door. Back forces imparted to a garage door, not designed into the components, can cause injury. Improper maintenance or lack of maintenance at all has resulted in serious bodily injury. Forced operation of a garage door, when one or more components have been damaged or broken, has resulted in serious bodily injury. In all cases, maintenance is a crucial and important aspect for the proper functioning of all door systems.
Unlike an overhead garage door, whether sectional or single panel, roll-up doors have a totally different type of operating system. When these doors are used they can be concealed in an upper or lower channel. These doors function similar to a roll-top desk door, except for how they store when not in the closed position. They typically roll up as they retract and require significant gear trains to reduce the effort required to move these doors up and down into position. Often the forces required to move these rolling doors require a type of reduction drive which allows a very heavy door to be operated effortlessly. These doors can be manually chain driven or can be automated using electric motors. Roll-up doors require more frequent evaluation and maintenance than a standard overhead garage door. Tracks that are mounted vertically on either side of the garage opening need more frequent maintenance and cleaning and are often blocked by foreign obstructions or damaged by collisions of some kind. These roll-up doors are often held open by some type of ratcheting action. The proper balance of these doors is usually more important than that of an overhead door, since the weight of these types of doors is usually much greater than that of an overhead door.
I have been involved in numerous garage door lawsuits where many different reasons for an injury have occurred. Having been retained as an expert witness for both the plaintiff and the defense, several common factors have been observed. In many cases, unqualified people have attempted to repair or install garage doors. They lack the knowledge, skills, or even the basic tools required to perform the job safely and properly. I have been retained as an expert by garage door manufacturers and installers to defend claims that they are not responsible for alleged product defects. In most cases, the components that failed failed as a result of abuse or improper installation by the end user. As stated above, many garage doors are not suitable for an untrained person to install. One exception to this relates to do-it-yourself garage door kits sold at local home centers. A homeowner could install the gate because these kits do not come with a professional grade hardware package that should or would require special knowledge for installation. These kits typically do not use torsion springs which require special knowledge, proper tools and job skills to install. The doors are typically for light use. Professional installation services are often available through a home center to help a homeowner in need of specialized installation. As with most trade-specific tasks, years of experience working as a professional installer qualify tradesmen for their contracting license. The average homeowner who watches some TV shows that give rough explanations of how to install garage doors is generally not qualified to install their own door. These “how-to” TV shows are not a replacement for the many skills acquired after working in the fields.
The above article is a very brief description of some types of garage doors. I have not given any specific details regarding proper business conduct nor have I listed any information regarding the potential for serious bodily injury.