Bifold and aluminium doors are some of the most precise doors in a home, and they are sensitive to alignment. The good news is that when they stop working it is almost always the mechanism, cylinder or alignment at fault — not the door itself — so a repair is a fraction of the cost of a replacement door set.
How bifold doors lock — and where they go wrong
A bifold door locks through its traffic (access) leaf, which carries a multipoint mechanism with shootbolts and hooks, while the folding leaves are held by drop bolts top and bottom. Because they run on a track and rollers, bifolds are very sensitive to drop and to debris in the track. The faults we see are leaves that no longer fold or align cleanly, drop bolts that miss their floor sockets, stiff handles, worn rollers, and gearbox failure. We realign the leaves, adjust or replace rollers, clean and clear the track, and replace shootbolt and gearbox mechanisms as needed.
Aluminium doors and slimline cylinders
Aluminium doors have a narrow stile (the upright frame around the glass), so they take a slimline, narrow-profile euro cylinder rather than a standard one. Fitting the wrong size is a common mistake: the cylinder must be measured precisely from both sides of the central cam, because a cylinder that protrudes is both insecure and prone to snapping. We carry and fit the correct slimline cylinders, and repair the multipoint hook locks and gearboxes that aluminium doors rely on.
Security upgrades
On both door types we can upgrade to an anti-snap cylinder cut to the exact length, which removes the most common attack point. On aluminium doors that means a correctly sized slimline anti-snap cylinder; on bifolds it means matching the new cylinder and mechanism to the existing cutouts so the door keeps working as designed.
Why repair beats replace
A new bifold or aluminium door set runs into thousands of pounds. The overwhelming majority of problems — stiff operation, a door that won’t lock, a leaf that drops — come down to alignment, a worn roller, or a mechanism or cylinder swap. Getting the right part fitted and the door properly aligned restores it to as-new operation for a fraction of the cost.