The door is the main part of the building which provides safety and privacy. Different varieties of doors are available according to the material, manufacturer, etc. There are different types of doors like flush doors, sliding doors, revolving doors, collapsible doors, rolling shutter doors, etc.
The collapsible door is one which can be opened or closed by slight pull or push. This door is used where the width of the door is large and space is insufficient to provide two-leafed hinged shutters to open. This door is fabricated from thin mild steel sections.
Courtesy - 123rf
Also Read: What is Rolling Shutter Door?
The collapsible door may be made of single or double shutters; it depends on the size of the opening. It does not require hinges for opening and shutters for closing. It occupies less space. Further, even the door is closed, seeing through is possible.
The collapsible door is fabricated from vertical pieces of rolled steel channels, 16 to 20 mm wide, joined together with the hollows of the channels on the inside; leaving a vertical gap between them of 12 to 20 mm. The roller is provided with both at their top and bottom side. The vertical channel is spaced at 10 to 12 cm center to center, and is joined to one another by means of hoop iron cross pieces or flats 16 mm to 20 mm wide and 5mm thick which allow the door to open or fold. The collapsible door is recommended for a maximum height 3 m. There is no restriction in width.
It may be classified into following types:
01. Doors fixed under the lintel,
02. Doors fixed outside the opening
03. Doors fixed inside the opening
04. Doors fixed on movable top and bottom channels with swinging arrangement on either side.
Also Read: Different Types of Doors
The collapsible door is used as main entrance doors of the residential building, shops, godowns, etc. It is a practical way of securing a point of entry. These entrance doors provide high security against burglars, vandals and other intruders. It is a popular choice for the protection of domestic windows and patio doors.