A bifold door that has become stiff, binds partway or no longer closes flush almost always has one of four things wrong: debris in the track, worn or misadjusted rollers, panels that have sagged on their hinges, or a shootbolt that has not fully retracted. The first and last are quick to check and cost nothing. The middle two are what most people are actually dealing with, and they are adjustable on most systems if you know where to look.
Start with the two free checks
Before adjusting anything, rule out the two causes that need no tools and account for a surprising number of complaints.
Check every shootbolt is fully retracted
Shootbolts are the vertical rods that pin non traffic panels into the head track and sill. A bolt that has only partly withdrawn drags in the track every time the panel moves, and it feels exactly like a roller problem.
Work along the set and confirm each bolt lever is fully in the open position and each bolt has pulled clear. This is the single most common reason a bifold suddenly becomes hard to fold, and it is often caused by debris in the sill hole stopping the bolt returning cleanly. We cover the hardware in our article on locking mechanisms for aluminium bifold doors.
Clear the tracks
The bottom track collects leaf litter, grit, sand, pet hair and, near the coast, salt. On a bottom rolling system the rollers run through all of it. On a top hung system the bottom guide does.
Vacuum the track along its full length rather than flushing it with water, which carries grit further in. Pay attention to the ends of the track and to the recess where panels stack, since debris accumulates there and only causes trouble when the door is fully opened.
Wipe out any old greasy residue while you are there. Oil based lubricant applied at some point in the past is a common contributor, since it holds dust and turns to paste.
Diagnosing by symptom
The way the door misbehaves points to the cause.
Stiff throughout its travel
Track debris or roller wear. Clean first, then assess. If it is still stiff on a clean track, the rollers or carriages are worn or need adjusting.
Stiff at one point only
Something is wrong at that position. A dented or bent section of track, a build up of debris, or a damaged roller that binds once per revolution. Run a finger along the track at that point and look for a burr or a flat spot.
Panels no longer line up when closed
The gaps between panels taper, wider at the top or bottom. This is panel sag, and it is the classic bifold complaint. Panels are heavy and hinged to one another, so over time the outer panels droop relative to the ones carrying them.
The bottom of a panel drags on the threshold
Either that panel has dropped on its carriage, or it has sagged on its hinges. Both are usually adjustable.
It closes but will not latch
Alignment. The traffic door has moved relative to its keeper, or the whole set sits slightly lower than it did.
It grinds or scrapes
Stop using it. A grinding noise usually means a roller has failed and the panel is bearing on the track directly, which damages the track quickly and turns a cheap repair into an expensive one.
Adjusting the carriages
Most Australian bifold systems have height adjustment built into the carriages, which are the roller assemblies connecting each panel to the track.
The adjuster is typically a hex socket on the carriage, reached through an access hole in the panel stile or from the top or bottom of the panel depending on whether the system is top hung or bottom rolling. Turning it raises or lowers that corner of the panel.
Three things are worth knowing before you start.
Adjust in small increments. A quarter turn is often enough to change how a panel sits. Large adjustments on one carriage transfer load to the others.
Work from the hinge side outward. The panel nearest the jamb carries the ones beyond it, so correcting it first often resolves what looked like a problem further along.
Mark where you started. If the adjustment does not help, you want to be able to return to the original position rather than compounding the problem.
If your system has no visible adjuster, or the access hole is covered by hardware you would need to remove, that is the point to stop and get someone in.
Panel sag and hinges
Hinge wear is the fault most often mistaken for a track problem.
Bifold panels hang from one another through their hinges, so a worn hinge lets the outer panel drop. The symptom is tapering gaps between panels and a set that no longer folds cleanly, and no amount of track cleaning improves it.
Some systems allow limited hinge adjustment. Many do not, in which case the hinges are replaced. That means supporting the panel while the hinge comes off, which is not a one person job.
Panels are heavier than they look. A 900 by 2100 panel with laminated glazing can weigh 60 to 80 kilograms. Dropping one causes serious injury and destroys the panel. If a repair involves taking a panel off, it needs at least two people and preferably someone who has done it before.
Weather seals
Brush and compression seals along the panel edges can swell, displace or lift, and a seal catching on the adjacent panel feels like binding.
Run a finger along the seals with the door open and look for sections standing proud of their race or curling. Reseating a displaced seal is straightforward. Replacing worn pile is inexpensive and available in standard sizes, though matching the height matters since too tall binds the panel.
Avoid silicone sprays near seals, since many seal materials do not tolerate them.
Coastal conditions
A bifold has more hardware than any other door in a typical home, which means more places for salt to work.
Across the eastern suburbs, Northern Beaches and Sutherland Shire, carriages, hinges and shootbolts corrode faster than the same hardware would inland. The sill is the harshest position, and bottom rolling systems suffer more than top hung ones for that reason.
Two practical consequences. Clean the tracks more often than you would think necessary, monthly rather than seasonally in exposed locations. And when hardware needs replacing, specify stainless where the manufacturer offers it, since the price difference is small against the labour of doing the job twice.
Compared with a sliding door, which has fewer panels and fewer moving parts, a bifold simply asks for more attention over its life. That is the trade for the full width opening. See our aluminium sliding doors if you are weighing the two.
Lubrication, and what not to use
Use a dry lubricant such as a PTFE or graphite based product, applied sparingly to the track and to moving hardware.
Do not use oil based sprays. Oil attracts dust, dust combines with it into a paste, and the mechanism ends up worse than before it was lubricated. This is the most common way a stiff bifold is made permanently stiff.
More is not better. A light application on a clean track outperforms a heavy one on a dirty track by a wide margin.
When repair stops making sense
Several situations mean the set has reached the end of its economic life.
The track is damaged. A bent, dented or worn track cannot be straightened reliably in place, and panels running on it will keep binding.
Multiple hinges have failed. One hinge is a repair. Several across the set means the hardware has reached its service life, and replacing them one at a time over a few years costs more than dealing with it once.
The frame has moved. If the opening itself is out of square from building settlement, adjusting the panels chases a problem that is not in the door.
Parts are unavailable. Older or discontinued systems can be difficult to source carriages, hinges and seals for. A set that is hard to repair today will not get easier.
The door is single glazed and failing. Money spent restoring a door that also lets in heat, cold and noise is money spent on the wrong thing. Our window replacement service includes assessment of whether an existing door or frame is worth keeping.
Keeping it working
Bifolds reward routine attention more than any other door type, because they have the most moving parts.
Vacuum the tracks every few months, monthly near the coast or on an unsealed road.
Operate every panel regularly, including ones you rarely fold back. Hardware that never moves seizes.
Check shootbolts retract fully each time you open the set.
Use dry lubricant only, sparingly, on a clean track.
Attend to stiffness early. A door that has started to feel different is cheap to adjust. One that has been forced repeatedly for a year usually is not, because forcing it damages the tracks and carriages that were merely dirty.
Our aluminium bifold doors are manufactured in Villawood with hardware specified for Sydney conditions.
Frequently asked questions
Why has my bifold door suddenly become hard to fold?
Check the shootbolts first. A bolt that has not fully retracted drags in the track and feels exactly like a roller fault. After that, clear the tracks, since debris is the next most common cause.
Can I adjust bifold door panels myself?
Usually yes. Most Australian systems have height adjusters on the carriages, typically a hex socket reached through the panel stile. Adjust in small increments and mark your starting position. If a panel needs removing, that is a job for two people at minimum.
Why do the gaps between my bifold panels taper?
Panel sag, caused by hinge wear. The outer panels droop relative to the ones carrying them. Some systems allow hinge adjustment and others require the hinges to be replaced.
What lubricant should I use on bifold tracks?
A dry lubricant such as a PTFE or graphite based product, sparingly, on a clean track. Never oil based sprays, which attract dust and eventually bind the mechanism worse than the original debris.
My bifold door is grinding. What should I do?
Stop using it. Grinding usually means a roller has failed and the panel is bearing directly on the track, which damages the track quickly and turns an inexpensive repair into a costly one.
How often should bifold doors be maintained?
Vacuum the tracks every few months, monthly near the coast. Operate every panel regularly, check shootbolts retract fully, and apply dry lubricant to a clean track occasionally.
Is it worth repairing an old bifold door?
Track cleaning, carriage adjustment, seal replacement and individual hinge replacement are all worth doing. A damaged track, several failed hinges, a frame that has moved out of square, or unavailable parts generally are not, particularly if the door is single glazed.
