Sliding & Patio Door Locks

Sliding patio doors and French doors are the most common doors onto a garden or patio, and because they sit at the back of a property, out of sight, they are a favourite target for forced entry. Both are sensitive to dropping and alignment, and both are almost always repairable rather than in need of replacement.

Sliding patio door locks

Sliding patio doors are held by hook bolts that pull into the frame, and their biggest weakness is lifting: a poorly secured sliding door can be levered up and off its track. We fit and adjust anti-lift devices and hook bolts, replace worn patio locks and the rollers that have let the door drop, and realign the sliding panel so it runs and locks smoothly. If your patio door has started to catch, scrape or lift in its frame, that is the warning sign to deal with before it stops locking altogether.

French door locks

French doors have a “first-locking” or slave leaf held by top-and-bottom shootbolts (the espagnolette), and a master leaf with a euro cylinder. The faults we see most are a leaf that has dropped so the shootbolts no longer line up with their keeps, worn or seized shootbolt mechanisms, and tired cylinders. We realign the leaves, replace the shootbolt and espagnolette mechanisms, and upgrade to correctly sized anti-snap euro cylinders so the doors lock firmly top and bottom again.

Worn rollers and dropped doors

Both door types ride on rollers or hinges that wear over time, and once the door drops even a few millimetres the locking points stop lining up — so it gets harder to lock and eventually won’t. Catching it early means a roller or hinge adjustment and a keep reposition rather than a failed mechanism and a door you can’t secure.

Security upgrades

Where a euro cylinder is fitted we upgrade to an anti-snap, TS007 3-star cylinder cut to the exact length — an over-long cylinder that protrudes past the handle is one of the easiest things to attack. On sliding doors we add or adjust anti-lift hardware, and on both we reinforce the keeps so the bolts have something solid to bite into. Because patio and French doors are a common back-of-house entry point, these upgrades make a real difference.

Frequently asked questions

My patio door lifts up slightly — is that a security risk?

It can be. Sliding doors can be levered up off their track if they are not properly secured, so lifting or scraping is worth dealing with early. We fit or adjust anti-lift devices and hook bolts and realign the door so it locks securely.

One of my French doors won't lock at the top and bottom — why?

Usually the leaf has dropped slightly or the shootbolt (espagnolette) mechanism is worn, so the bolts no longer meet their keeps. We realign the leaf and replace the shootbolt mechanism so both bolts engage firmly again.

Is it cheaper to repair a sliding or patio door than replace it?

Almost always. Most problems are worn rollers, alignment, or a lock or cylinder swap, which cost a fraction of a new door. We diagnose the actual fault and repair it rather than replacing the whole door.