Whether you are replacing an existing door or pricing doors for a new garage, you must measure properly to be sure you order the right size. The illustrated instructions below explain the process.
Measure the width and height of the door opening in millimetre.
Measure for sideroom. You will need 10centimetre on each side to install the vertical track for standard torsion springs,
Measure your headroom -- the distance between the top of the door opening (jamb header) and the ceiling (or floor joist). You will need 30cm headroom for standard torsion springs . If you have restricted headroom, a "low headroom" track may be available for your door,You will need 17cm headroom . Be aware that electric operators may require additional headroom.
Measure your backroom -- the distance from the door opening to the back wall of the garage. Door height plus 100cm is required. Be aware that electric operators may need additional.