3 Factors for Determining Garage Door Cable Length
Ensuring that the garage door cable length is correct is vital for a door to balance and function properly. There are 3 things to consider for determining the proper cable length.
- The height of the garage door
- The drum being used
- The type of lift
Garage Door Height
The height of the garage door is one of the factors used when determining the proper length of cable needed. To measure the height of the garage door, measure from the bottom of the garage door and round to the nearest 3” door height.
Garage doors have multiple ways to be opened. Standard lift (commonly seen on most residential homes), hi-lift (when the door needs to travel out of the opening before heading into the horizontal tracks), and vertical lift (commonly found in commercial settings). Below we go into detail for each lift type, the drums they use and how the SSC Spring Engineering App makes calculating the cable length simple.
For doors that use torsion springs, most residential garage doors use standard lift when there is approximately 12” of headroom. For doors that use extension springs, standard lift needs at least 8.5” of clearance.
Hi-lift garage doors are used when there is a need for increased space below the open door. Garages that have high ceilings for things such as a car lift would be a good use for a hi-lift door.
Vertical lift doors are more common in a commercial setting where there are large buildings with high ceilings. The required ceiling height will need to be at least the height of the door. Many dock doors in industrial settings are configured with hi-lift.
PRO TIP: Some garage doors use tracks that follow the pitch of a roof. Be sure to factor this in. Our app makes this easy to do.
Depending on the lift type of the garage door, it will require a specific corresponding drum.
Standard Lift Drums
Standard lift drums are designed to have a consistent cable wrap across the width of the drum to allow for the lift of the garage door.
Hi-lift drums have a raised portion and a flat portion, like a standard lift drum. The raised portion helps the garage door open faster to cover the longer or hi-lift portion of the door travel.
Vertical Lift Drums
Vertical drums are a tapered drum whose wraps of the cables gets smaller as the door travels. These drums allow for the door to be lifted vertically without weight transferring onto the horizontal tracks.
Cable Wire Size
The cable wire size is dependent on the drum used and the height & weight of the door. Each drum will have a maximum cable diameter. Other factors for the cable wire will depend on the door height and weight. For larger and heavier doors, you will need a larger drum and/or cable to lift the door safely and properly.
Solution – SSC Spring Engineering App
The SSC Spring Engineering app helps you quickly solve proper cable length and other cable wire information, in a matter of minutes.
Determining Cable Length
In the SSC App you can quickly find what the cable length should be for the garage door in 4 steps.
- Determine the drum used on the garage door. Most drums should have a part number on them. If it does not, please see – measuring a drum (Link to blog for measuring a drum.).
- Open the SSC Spring Engineering App and navigate to the Spring Engineering portion.
- Select your drum.
- Tap the blue info icon.
In the information section, when the cable length formula is known for that drum, it will be displayed here. It will also provide you with the cable diameter size to be used with that drum.
Cable Length Formats (Use the SSC App to determine # of inches)
- Standard Lift Doors – Measurement from floor to shaft center + (x) # of inches.
- Hi-Lift Doors – Measurement from floor to shaft center + (x) # of inches – amount of hi-lift.
Vertical Doors – Measurement from floor to shaft center + (x) # of inches – door height.
Safety Disclaimer: In order to see all procedures completely, there may be safety measures that are not taken by our actors. Be sure to follow any and all proper safety requirements and refer to your manufacturer’s installation manual for details. Your health and safety is the #1 concern. Failure to understand/follow the recommendations in the course could result in property damage, personal injury or death. While all efforts are made to provide accurate information and guidance, it is impossible to predict all door circumstances. Accordingly, the user agrees that the user of this video; products and information contained herein are at your own risk. In no event shall Service Spring be liable for any property damage, personal injury/death, or any other loss or damage that may result from your use of the information and products provided on this video. All information contained within this site is provided “as-is” without warranty expressed or implied. User assumes all responsibility/risk for use of information and products purchased. If you have any doubts about your ability to perform the work safely, we recommend you contact another door professional to complete your repair.