A double steel door is a door made from two panels of steel separated by a layer of insulation. There are a number of applications for double steel doors, with these doors typically being seen in commercial and industrial settings, although people can also install them at home. Many manufacturers make double steel doors along with matching frames, and the doors can be installed by any competent contractor. Manufacturers can also provide customers with detailed specifications which provide information about the size of a door and frame, the environments where it can be used, and how to install the door properly.
One of the primary purposes for installing a double steel door is fire safety. In a structure which is designed to be fire resistant, double steel doors provide a method of passage through a fire-resistant wall without impairing fire safety. The doors are typically given a rating which indicates how many hours of high temperatures they can withstand, and they may be required by law in many structures, such as schools. The double layered design paired with insulation makes it very difficult for a fire to penetrate the door unless temperatures climb extremely high or the fire burns for many hours.
Double steel doors also provide sound resistance, thanks to the layer of insulation. Some manufacturers stock doors which are unfilled, allowing customers to order the insulation product they want, and several companies offer insulation brands which are designed to provide acoustic baffling. Usually soundproofing is not the only reason to install a double steel door, but it can be a pleasant benefit in noisy environments where fire safety is a concern.
These doors are also used as security doors. It is difficult to penetrate a double steel door which has been hung correctly and outfitted with an appropriate lock. Using such doors can reduce security concerns for a structure, making it safer to work in. In high security environments, double steel doors may be legally required to protect data or other sensitive material.
A double steel door may be solid or equipped with a viewing window. The security and fire ratings of the door will be altered by the window, with the size, thickness, and level of reinforcement in the window all playing a role in how the door can be rated. These doors may be installed indoors to provide fire resistance and separation between rooms and corridors in a building, and they can also be installed at entrances.