French Door Repair in London: Shoot Bolts, Locks and Alignment

French doors are two doors that meet in the middle, and that is what makes them tricky. One leaf, the master, carries the handle and main lock. The other, the slave leaf, is held shut by shoot bolts at the top and bottom. Both leaves have to line up with each other and with the frame for the lock to engage. When one drops, or a shoot bolt stops working, the doors won't close together or won't lock. Mark repairs French doors on uPVC, aluminium and timber frames.

Shoot bolts and multipoint locks repaired
Both leaves realigned at the meeting stiles
Hinges adjusted or replaced
Glass replaced in the existing door
Fixed price confirmed before any work starts

Shoot bolts are the most common failure. On many uPVC French doors they are worked by a small lever or handle on the edge of the slave leaf, which pushes rods into the frame head and threshold. The gearbox or rods can break, or the bolt holes in the threshold fill with grit so the bolt can't drop in. If the slave leaf isn't secured, the master leaf has nothing solid to lock against, and the pair can be pushed open even when locked.

Meeting-stile alignment is the next issue. If either leaf drops on its hinges, the two vertical edges where they meet no longer line up, so the hooks on the master leaf miss their keeps on the slave leaf. You see it as doors that need pushing together before they lock, a gap at the top or bottom of the meeting edge, or a handle that needs forcing. Adjusting the hinges on both leaves restores the line, and our guide to French doors that won't close explains what to look for.

The master leaf usually has a multipoint lock, the same type found on single uPVC doors. A failed gearbox, worn cylinder or snapped hook is replaced in the same way, and for detail on lock and mechanism work see our door and lock repairs page. Glass in French doors is usually large and must be safety glass; a cracked or misted pane is replaced in the existing leaf.

Timber French doors bring their own faults, such as swelling in wet weather and worn hinges, and aluminium pairs can suffer stiff shoot bolts and tired seals. In each case the aim is the same: both leaves hanging true, the slave leaf held firmly, and the lock engaging with a light lift.

Small habits help French doors last. Keeping the threshold bolt holes clear of grit, closing the slave leaf first and securing its bolts before locking the master leaf, and not leaving the pair swinging in the wind all reduce wear on the hinges and locks. If the doors have started to need a push or a lift to lock, getting them adjusted early is far cheaper than waiting for a gearbox to fail.

How the repair works

1. Describe or photograph Tell Mark whether the doors won't meet, won't lock, or the slave leaf won't hold.
2. Fixed price A fixed price is confirmed before any work starts.
3. Align and repair Both leaves realigned, bolts and locks repaired, and the pair tested closing and locking.

Frequently asked questions

Why won't my French doors close together?

Usually one or both leaves have dropped on their hinges, so the meeting edges no longer line up. A blocked or broken shoot bolt on the slave leaf can also stop the pair closing properly.

Can you replace the glass in a French door?

Yes. The glass is replaced in the existing leaf, using safety glass as door glass requires. Misted double glazed units in French doors are replaced the same way.

Can French door locks be repaired?

Yes. The multipoint lock on the master leaf and the shoot bolts on the slave leaf are both replaceable parts, so the doors themselves stay in place.