Up-and-over garage door - how it works in detail

If you have contemplated how the common up and over garage door works, here is an explanation.

In simple terms the movement and function of the door is controlled by springs, of which there are normally three. These springs allow what should be the smooth transition of the door as it tilts inwards and then moves up and over than door entrance void.

So where are these springs and what do they do?

The first spring is a long tension spring and it sits horizontally in the flap at the top of the door. This spring is known as a torsion spring because it tightens as the door is closed and relaxes when the door is opened. This spring has the appearance of a wound up wire and it normally runs something close to the full width of the door. It makes the opening and closing of the door possible by producing resistance.

The next springs are in a pair and they can be found one either side of the door opening. They are often referred to as extension springs. Extension springs are just simple springs like the ones that you would find in a toy, only larger. They have no tension within them and they expand or contract when the door is opened or closed. It is these springs that perform the “effort” element of the door’s opening and closing action. In an automated door system these springs are operated by a remote controlled motor.

What does the door move on?

Using the power and balance produced by the springs the door's motion is directed by tracks that run either side of the door opening and extend into the roof space. The door locates into these tracks using wheels or rollers and these guide the door as it is opened or closed.

Some other components like fixings, bearings and cable drums enable the different springs, the door, and the track and rollers to work as a single smooth and efficient unit. Motorization can also be added.

There are of course two different versions of the up and over garage door, namely the retractable and the canopy, and the retractable version is slightly more complex with a more elaborate track mechanism.