Garage Door Sitting Crooked or Stuck in the Opening

What causes it

These are the causes we find most often, in roughly the order we check them.

1. 1

   One lift cable stretched or unwound on its drum

   The two cables must wrap the same number of turns on their drums, or one side of the door lifts further than the other. A cable that has stretched, or one that has slipped a groove on the drum, drops that corner and the door climbs into the opening on the diagonal.

   What you can check

   Close the door and look at the gap along the top edge, then along the floor. A wedge-shaped gap at either, or a bottom rail that is not parallel with the slab, means the two sides are no longer travelling together. Look at both cables for slack or loose wraps.

   What we do

   We take the tension off under control, re-wrap both drums to the same setting, and replace stretched or frayed cables as a matched pair. Then we re-square the door and cycle it several times to confirm it holds. Cables are never replaced singly.

2. 2

   Broken hinge letting a panel lag

   Sectional doors pivot on hinges numbered by row. A hinge cracked at the knuckle, or one whose fixing screws have torn out of the panel skin, lets that side of the joint move out of step. The panel above lags, the door folds unevenly, and it binds on the track curve.

   What you can check

   With the door shut, look along every hinge on both sides and down the centre. A cracked leaf, a missing screw, a hinge standing proud of the panel, or a bright wear mark where metal has been rubbing metal, are all visible from inside.

   What we do

   We fit the correct numbered hinge for that row, because the wrong number changes the door's geometry. Where screws have torn out of the panel we add backing plates so the new hinge has something solid to hold, rather than chasing the same failure again in six months.

3. 3

   Bottom bracket pulling out of the panel

   The bottom bracket carries the cable and the bottom roller, which means it takes the entire lifting load for that side. Corrosion in the bottom rail, or a door that has been reversed into, works the bracket loose. That corner drops and the door racks in the frame.

   What you can check

   Look at both bottom corners from inside with the door closed. Elongated bolt holes, a bracket standing away from the panel, rust bleeding out from under it, or a bottom rail deformed around the fixings all mean the bracket is on its way out.

   What we do

   This must be done with the spring tension controlled, because the cable is anchored to that bracket. We support the door, fit a new bracket with proper fasteners, and replace the bottom rail section where the metal is too far gone to hold a fixing.

4. 4

   Seized roller dragging one side

   A roller whose bearing has collapsed skids rather than rolls. That side sees far more friction than the other, so it lags on the way up and leads on the way down. Over a few months the difference is enough to twist the door and jam it at the same point every cycle.

   What you can check

   Run the door slowly and watch each roller in turn. Any roller that is not spinning, or that squeals and leaves a bright polished stripe in the track, has seized. You can also see the difference in the gap between the door edge and the jamb on each side.

   What we do

   We replace the rollers as a full set with nylon-tyred units on sealed bearings, check every hinge for elongated stem holes, and re-align the tracks. Swapping one seized roller in a set of twenty-year-old steel ones simply moves the problem to the next one along.

5. 5

   Vertical tracks out of plumb after jamb movement

   Perth's clay soils move with the seasons and timber jambs shrink as they dry. The tracks are fixed to that timber, so when the jamb twists the track spacing changes. Too narrow and the door binds, too wide and it wanders. Either way it stops sitting square in the opening.

   What you can check

   Hold a spirit level against each vertical track. Both should be plumb and the same distance from the door edge top to bottom. Look for gaps behind the brackets and lag screws standing proud, which show the timber has let go of the fixings.

   What we do

   We re-plumb both tracks, reset the spacing to the manufacturer's dimension and re-fix into sound timber, adding packers or a steel angle where the original fixing points have chewed out. Where the jamb has rotted we say so plainly, because that needs carpentry first.

6. 6

   The door was racked by closing onto an obstruction

   If something stops one bottom corner while the other keeps travelling, the door twists in the opening within a single cycle. The panels stay put but the whole assembly is out of square, the rollers bind in the tracks, and the door jams solid on the next attempt.

   What you can check

   Look for a diagonal shadow line at the floor, one bottom corner sitting higher than the other, or a fresh dent in the bottom panel. Note whether the safety reversal failed to trigger when it happened, because that is a separate fault worth telling us about.

   What we do

   We square the door back up, replace any bent brackets, hinges or panel that took the load, then re-tension and re-track it. Before we leave we test the auto-reverse properly, because a door that racked itself on an obstruction should have stopped and did not.