How to Secure Patio Doors With Locks: Match the Lock to the Door

A patio door can feel secure because the handle turns and the key locks, but that does not always tell you whether the whole door is holding properly. A sliding panel may still have too much lift in its track, a French-door pair can depend on one weak passive leaf, and a bi-fold may stop locking cleanly when the panels drop out of alignment.

Learning how to secure patio doors with locks starts with the door you already have, then choosing hardware that solves a specific weakness. This guide explains the most useful lock options for sliding, French and bi-fold doors, when repair or replacement makes more sense, and how to add monitoring without distracting from the physical security of the entrance.

Key Takeaways

• Match the lock to the way the door moves. Sliding, French and bi-fold doors need different types of protection.
• Sliding doors need both locking and anti-lift protection. A stronger hook lock does not stop a panel being lifted if the track allows too much vertical movement.
• French doors depend on both leaves. The passive leaf, top and bottom bolts and any exposed hinge side matter as much as the everyday handle.
• A 3-star euro cylinder is useful only when the rest of the door is sound. Alignment, handles, keeps and frame condition still matter.
• Repair structural problems before adding more hardware. A loose frame or repeatedly misaligned doorset may need professional repair or replacement rather than another surface-mounted lock.

Check the Door Before You Buy Another Lock

A stiff handle or rattling panel does not automatically mean the lock itself has failed. Start by checking whether the door closes squarely and whether every existing locking point reaches its keep. That prevents you spending money on a new cylinder when the real problem is alignment, worn rollers or a loose frame.

If the frame is modern uPVC or aluminium and you are unsure what is inside it, avoid drilling for a generic lock until you know where the reinforcement and operating mechanism sit.

A Master Locksmiths Association member or professional door installer can identify a suitable fixing point without risking damage to the door or frame.

How to Secure Patio Doors With Locks, by Door Type

The best lock is the one that addresses the weakness of your own door. For securing patio doors, start with the existing primary lock, then add only the extra measures that solve a different problem.

Sliding patio doors: combine a reliable lock with anti-lift protection

A sliding door needs two separate checks: does the lock hold it shut, and can the moving panel stay securely in its track? Police.uk’s door security guidance specifically recommends an anti-lift device on sliding patio doors so they cannot be lifted out of the frame.

If the original hook or multi-point lock works properly but you want another locking point, a purpose-made sliding-door bolt, key-operated patio lock or compatible foot bolt can add resistance.

A fitted security bar can also block the panel from moving sideways if the main lock is forced. It does a different job from an anti-lift device, so one does not automatically replace the other.

Good patio door security for a slider therefore comes from three things working together: the panel stays in its track, the main lock engages cleanly, and any secondary lock or bar adds another useful barrier without making the door awkward to use.

French patio doors: secure the passive leaf and hinge side

With French doors, a strong lock on the leaf you open every day is not enough if the second leaf can move. Check that the passive leaf is held firmly by its top and bottom bolts or another suitable mechanism, then make sure the active leaf locks cleanly against it.

Traditional timber pairs may use a British Standard five-lever mortice lock with supplementary bolts, while many modern uPVC and aluminium doors use multi-point locking with a euro cylinder.

If the doors open outwards, use suitable hinge-side protection so exposed hinges do not become the easiest point of attack.

Bi-fold patio doors: make every locking point engage

Most modern bi-fold doors already have multiple locking points distributed across several leaves. The priority is making sure they all engage as intended.

Clear debris from the running track, check that adjacent panels meet correctly and confirm the main handle and shoot bolts work smoothly. A dropped panel or damaged keep can leave part of the assembly unsecured even when the key has turned.

Do not fit a sliding-door bar across a bi-fold or drill through its frame without the manufacturer’s guidance. If the mechanism has failed, look for the exact replacement gearbox, cylinder, handle or shoot-bolt assembly used by your door system.

Choose Extra Locks That Solve a Specific Weakness

Once the existing lock works properly, compare upgrades by what they actually do. More hardware is useful only when it adds a different type of resistance.

Choose the Right Euro Cylinder Where Your Door Uses One

If your patio door uses a euro-profile cylinder, the cylinder should be both security-rated and correctly sized. West Yorkshire Police recommends a TS 007 3-star solution as the minimum when upgrading, with a 3-star cylinder the preferred option; Sold Secure Diamond Standard (SS312) cylinders are also recognised.

Measure the cylinder so it sits flush with the handle or door furniture rather than projecting where it can be attacked. Also check the handles and the surrounding multi-point mechanism. A high-rated cylinder does not fix a dropped door, damaged keep or loose frame.

Know When Repair or Replacement Makes More Sense

Extra locks are worthwhile when the frame and existing mechanism are fundamentally sound. Replacement becomes more sensible when the frame is cracked or loose, several keeps have pulled away, the doors repeatedly fall out of alignment, or the locking system remains unreliable after repair.

If you are replacing the whole entrance, compare complete doorsets rather than individual locks. Secured by Design explains that PAS 24 testing applies to the complete doorset - the frame, leaf or leaves, hardware and integral panels - rather than certifying a single component in isolation. That makes it a more useful benchmark when you are considering a major upgrade.

Make Every Lock Work in Daily Use

Even a good lock offers less protection if it is only partly engaged. These checks are simple, but they matter more than adding hardware you rarely use.

• Close every leaf fully before locking. On a multi-point system, lift the handle where required and turn the key so the hooks or bolts engage.
• On French doors, check the passive leaf is secured as well as the everyday access leaf.
• On bi-folds, confirm the shoot bolts and locking points are engaged rather than assuming the key turn secured every panel.
• Keep sliding tracks clear and arrange adjustment if the door starts rattling, catching or becoming difficult to lock.
• Make sure any added bar, bolt, or handle device can be released quickly from inside, particularly if the patio door is used as an escape route.

Add Visibility Once the Door Itself Is Secure

Locks resist entry; lighting, alarms, and security cameras help you see what is happening around the patio.

Use lighting and door contacts for simple alerts

A door-contact alarm tells you when the patio door opens, while a motion-activated light makes a dark garden route or side passage easier to see. Position lighting so it covers the approach without shining directly into the camera lens or neighbouring windows.

Position an outdoor camera around the approach

Place the camera outside rather than filming through the patio glass, as reflections can interfere with useful footage, especially at night. Aim it so you can see the door itself as well as the route someone would normally take to reach it.

For this type of location, look for security cameras with reliable night vision, useful motion alerts and a recording method that suits how you want to monitor the area. Also check that the chosen position has dependable Wi-Fi or wired connectivity and access to the required power source.

Try to keep the camera focused on your own property. The ICO’s home CCTV guidance advises homeowners to avoid capturing more of neighbouring property, communal areas or public spaces than necessary.

If your camera records beyond your property boundary, data protection rules may apply, including requirements around signage, secure footage storage, and handling recordings appropriately.

If your patio also leads to a side passage with garage access, our garage security guide covers the extra locks and storage precautions for that separate entrance.

Choose Camera Coverage for the Patio and Other Entrances

Different entrances often need different types of camera coverage. For a patio or rear garden, the best option depends on where the camera can be mounted, how the area is powered and whether you want lighting, continuous monitoring or flexible installation.

SoloCam S340 for flexible garden coverage

For a patio that opens onto a garden without a convenient outdoor power point, the SoloCam S340 gives you solar-assisted monitoring without running a new mains cable.

Best for: Rear patios, side passages and garden approaches where one event-recording camera needs a wide adjustable view.

• Dual-camera detail: A 3K wide-angle camera and 2K telephoto camera provide 8x hybrid zoom for both the patio and activity farther down the garden.
• Pan-and-tilt coverage: 355° horizontal and 70° vertical movement helps one mounting point cover the doors and nearby paths.
• Solar-assisted power: The removable 2.2W panel supports normal battery operation when it receives suitable sunlight.
• Local storage: 8GB of built-in storage keeps motion-triggered clips locally without a required monthly storage subscription.

Floodlight Camera E340 for lighting and continuous video

Where there is a suitable hardwired position above or beside the patio, the Floodlight Camera E340 combines bright adjustable lighting with dual-camera tracking and 24/7 recording.

Best for: A dark rear entrance or patio where you want both illumination and a continuous video timeline.

• 2,000-lumen lighting: Two adjustable panels illuminate the doors, steps and surrounding approach.
• Two views from one fitting: A 3K wide-angle camera and 2K telephoto camera provide up to 8× hybrid zoom, with pan-and-tilt tracking and on-device person, vehicle and pet detection.
• 24/7 local recording: Continuous footage is available with a microSD card up to 128GB or HomeBase S380.
• Hardwired power: The camera uses 100-240V AC, making it suitable for a permanent powered position.

Video Doorbell S4 for complementary front-door coverage

If you also want to see visitors and deliveries at the front of the house, the Video Doorbell S4 adds a separate panoramic view of the doorstep alongside the rear-patio setup.

Best for: homes that want dedicated coverage at both the front door and rear patio.

• 180° × 180° panoramic view: Captures visitors from head to toe while also showing the area directly in front of the door, where parcels are often left.
• 3K detail with intelligent tracking: High-resolution video helps preserve useful facial and scene detail, while OmniTrack™ follows detected movement across the frame.
• Wired monitoring and local storage: Wired power supports 24/7 snapshot recording, with built-in eMMC storage and microSD expansion for local footage without requiring a cloud subscription.

If you need a different installation style or feature set at the front entrance, explore our wider video doorbell range to find an option that suits your doorway and monitoring needs.

Conclusion

The most effective way to secure patio doors with locks is to match the hardware to the door you already have. Sliding doors need anti-lift protection as well as reliable locking, French doors depend on both leaves and the hinge side, and bi-folds need every locking point to stay aligned.

If the frame or mechanism is failing, repair or replacement should come before extra accessories. Once the physical door is sound, lighting and well-positioned camera coverage can add useful visibility around the garden and other entrances.

FAQs

How do you burglar proof a patio door?

You cannot make a patio door completely burglar-proof, but you can make forced entry much harder. Keep the frame, hinges and locks in good condition, add anti-lift protection to sliding doors, and use secure locks suited to the door type. Police guidance also recommends PAS 24-rated replacement doors and TS 007 3-star euro cylinders where applicable. Lighting, alarms and outdoor cameras can add further protection.

What type of patio door is most burglar-proof?

Modern French, sliding and bifold patio doors can all provide strong security when properly designed and installed, so no single style is automatically the most burglar-proof. For a new door in the UK, look for a complete doorset tested to PAS 24, together with secure multi-point locking and laminated glazing. Sliding doors should also include anti-lift protection to prevent the panel being lifted from its track.

How to add extra security to patio door?

Start with the weak point of your existing door. Sliding patio doors may benefit from an anti-lift device or additional patio-door lock, while French doors can use suitable top-and-bottom security bolts. If you have a euro-cylinder lock, consider a TS 007 3-star cylinder. You can also improve surrounding security with motion lighting, a door sensor and a camera covering the patio approach.