Springs · Hamilton
Extension Spring Replacement
The home inspector's report on the house you are buying flags the garage door: extension springs with no safety cable running through them, coils showing rust, and a door that sank when he lifted it partway. The seller has never had it looked at.
Extension Spring Replacement
In plain words
Extension springs are the two long coil springs that run beside the horizontal tracks of a garage door, one on each side. They stretch as the door closes and pull back as it opens, and that pull is what makes a heavy door feel light. Replacement puts a new, matched pair on the door. The technician opens and secures the door so the springs are slack, removes the old set, fits springs rated for the door's actual weight with containment cables through their centres, threads the lift cables over the pulleys, and adjusts both sides until the door balances. The opener is reconnected and tested last.
How the visit goesOpen the door by hand and it drifts back down on its own, a little at first and then all at once. Nothing is broken that you can see, but the springs along the tracks look tired, rusty and slightly sagging.
Hamilton
How the visit goes
Securing the door with the springs slack
An extension spring is stretched tight when the door is closed and nearly relaxed when the door is fully open, so the first move is to get the door up. The technician pulls the opener's release, raises the door by hand if it will go, and clamps both vertical tracks below the bottom rollers so the door cannot come down. If a broken spring has left the door stuck partway, it is lifted and supported with the weight taken on clamps and props before anything else is handled. With the door held open, the springs, pulleys and hooks can be examined and removed like ordinary hardware, which is the whole reason the sequence begins this way.
Threading the containment cables
Before a spring is hung, a containment cable is fed through the centre of its coil. One end is anchored at the rear, to the hanger or the framing behind it, and the other is run forward past the pulley and fixed to the bracket at the front of the track or to the wall, with enough slack that the cable never carries load while the spring works. The cable is checked to be clear of the pulley wheel and the lift cable so nothing rubs. Both sides are done the same way, whether or not the old installation had them. A spring that breaks in future is held on the cable rather than crossing the garage.
Checking the balance yourself
You can confirm the springs are still doing their share without going near them. With the door closed and nobody in the opening, pull the opener's red release cord so the trolley lets go of the door. Lift the door by its handle to roughly hip height and take your hands away. A door on good springs stays about where it is; if it sinks to the floor the springs have weakened, and if it rises on its own they are pulling harder than the door weighs. Either way it is a call rather than a job for you. Reconnect the opener the way your manual describes, usually by running it once.
Extension Spring Replacement
In the van
- Replacement rollers and hinges
- Rear spring hangers and angle iron
- Track clamps or locking pliers
- Containment (safety) cables
- Garage-door spray lubricant
What affects the quote
Same fees day, night or weekend
1Converting to torsion instead
Where the garage has the headroom, some owners take the opportunity to move to a torsion system. That is a different job with different hardware and is quoted as its own option.
2Weight added since the door went in
Insulation panels, windows or a wood overlay fitted after the original springs mean a heavier rating than the old pair. The door is weighed and the quote reflects the door as it is now.
3Door weight and size
Spring rating follows the door's weight, and a wide insulated door or a wood door takes heavier springs than a light single. Weight and height together set the parts on the quote.
Extension Spring Replacement: questions
I added insulation and windows to the door. Does that affect the springs?
Yes, and it is one of the more common reasons a pair of springs is suddenly found wanting. Insulation panels, glazed sections, a wood overlay or a new steel skin all add weight the original springs were never chosen for, so the door grows heavy and the opener strains. When the springs are replaced, the door is weighed as it is now, and the new pair is rated for the door you actually have.
Will the lift cables be changed as well?
They are inspected every time and changed when they show fraying, rust at the bottom loop, or a kink from having jumped a pulley. Cables and springs are generally the same age, and with the door already open and the springs off, fitting new cables adds little to the visit. Bright, tight strands with clean loops can stay and are simply re-routed over the pulleys and set to the new springs.
Why does the door slam down the last bit?
A door that drops the final stretch is telling you the springs are no longer holding it. As an extension spring loses its temper it gives less pull near the bottom of travel, where the door needs the most support, so the door falls that last foot. Fresh springs matched to the door's weight bring the door down under control and take that shock off the bottom section and the opener.
Springs & Hardware
Extension Spring Replacement near you
In Hamilton we work on garage doors of every age and size: single and double residential doors, insulated and uninsulated, wood and steel, plus commercial rolling and sectional doors. The service pages explain the repairs, replacements and installations that apply to each.