Composite Door Repair in London: Locks, Hinges and Glass

Composite doors are built differently from uPVC doors. The leaf is a solid slab, usually a foam or timber core inside a tough outer skin, which makes them heavier and stronger. That weight and that construction change how they fail and what can be repaired. The good news is that the parts that usually go wrong, the multipoint lock, the cylinder, the hinges, the glass and the seals, are all replaceable. Mark repairs composite doors in their frames, so you keep the door you chose.

Multipoint locks and cylinders repaired on composite doors
Hinges adjusted or replaced to realign heavy door slabs
TS007 3-star anti-snap cylinders available
Fixed price confirmed before any work starts
Often same-day where the diary allows

The extra weight of a composite slab puts more load on the hinges, so composite doors drop out of line just as uPVC doors do, sometimes faster. The signs are the same: catching on the frame, a draught along one edge, and a handle that needs a hard lift before the door will lock. Adjusting or replacing the hinges brings the door back into line and takes the strain off the lock. Our door hinge repairs page explains the adjustments in more detail.

Many composite doors become hard to lock in summer. The dark outer skin absorbs heat from direct sun, and the slab can bow slightly, so the locking points no longer meet the keeps evenly. Adjusting the keeps and hinges to suit usually cures it, and is far better than forcing the handle, which wears the gearbox. If the gearbox has already failed, it is replaced along with the cylinder if needed; see our door and lock repairs page for lock work.

Glass in a composite door usually sits in a cassette, a frame that clips or screws into the slab from both sides. Decorative and obscure glass panels can be replaced by removing the cassette, and where an exact decorative pattern is no longer made, Mark can source a close match or a plain obscure alternative. Door glass must be safety glass, and any replacement is specified to suit.

What can't be repaired is serious damage to the slab itself, such as a split skin or a crushed core after forced entry. In that case Mark will tell you honestly, because we repair rather than sell new doors. For most composite door faults, though, a replacement part restores the door. For other door types see our uPVC door repairs page.

Seals and thresholds wear too. The rubber gaskets around a composite door compress over years of closing, and a worn threshold seal lets in draughts and rain at floor level. Both can be renewed without removing the door. If your cylinder is old or you have recently moved home, it is also a good moment to fit a TS007 3-star anti-snap cylinder while the lock is being worked on.

How the repair works

1. Send a photo A photo of the door, the lock edge and any damaged glass helps identify the parts.
2. Fixed price Mark confirms a fixed price before any work starts.
3. Repair and adjust Parts replaced, door realigned and tested to open, close and lock smoothly.

Frequently asked questions

Can composite doors be repaired?

Yes. Locks, cylinders, hinges, glass, seals and handles can all be replaced on a composite door. Only serious damage to the slab itself, like a split skin, is beyond repair.

Can you replace the glass in a composite door?

Usually, yes. The glass sits in a cassette that can be removed from the slab, so the panel is replaced without changing the door. Decorative patterns are matched where possible.

Why is my composite door hard to lock in summer?

Sun heats the outer skin and the slab can bow slightly, so the locking points no longer line up with the keeps. Adjusting the keeps and hinges usually fixes it without forcing the lock.