Patio Door Security: How to Protect Sliding, French and Bi-Fold Doors

Patio doors are used every day, so it is easy to assume that closing and locking them is enough. But a sliding panel can still be vulnerable to lifting, a pair of French doors depends on both leaves closing securely, and a bi-fold lock only works properly when the panels stay aligned.

Good patio door security starts with checking how your own doors actually move, close and lock, then strengthening the weak points that matter. This guide explains practical upgrades for sliding, French and bi-fold doors, when stronger glazing or a replacement doorset is worth considering, and how lighting, alarms and cameras can help you monitor the garden approach.

Quick Answer: How Do You Improve Patio Door Security?

If you are wondering how to secure patio doors, start with the way your door opens.

• For sliding doors, deal with lifting as well as locking. The panel should stay securely in its track and the main lock should engage fully.
• For French doors, secure both leaves. Check the passive leaf, top and bottom bolts, hinges and frame rather than focusing only on the active handle.
• Look at the complete doorset. A strong cylinder cannot compensate for a loose frame, damaged track or weak glazing.
• Use monitoring as the next layer. Lighting, alarms and cameras help you see activity around the patio, while the locks, frame and glazing remain the first line of resistance.

Check the Weak Points Before You Buy More Hardware

A glass patio door is not automatically insecure. Problems usually come from a worn lock, poor alignment, missing anti-lift protection or a weak frame. A quick inspection helps you spend money where it will actually make a difference.

How to Secure Sliding, French and Bi-Fold Patio Doors

The most useful upgrade depends on how the door moves. Start with the weakness that is specific to your design, then add a second layer only where it solves a different problem.

Sliding patio doors: stop lifting and strengthen the lock

For sliding patio door security, check two things separately: whether the moving panel can be lifted and whether the lock holds it firmly shut. Police.uk’s door security guidance specifically recommends an anti-lift device on sliding patio doors so the panel cannot be raised out of the frame.

If the door has noticeable vertical play, worn rollers or poor alignment, have that corrected first. Then add a compatible anti-lift block or device. A well-fitted key-operated patio lock, foot bolt or secondary bolt can provide another locking point, while a purpose-made security bar physically blocks the panel from sliding if the main lock is defeated.

Good security for sliding patio doors combines anti-lift protection, a lock that engages fully and a frame that stays rigid; the devices are most useful when each one addresses a different weakness.

French doors: secure both leaves and the hinge side

A pair of French doors is only as secure as the leaf the main door closes against. Check that the passive leaf is held firmly with top and bottom bolts or another suitable locking arrangement, and make sure the active leaf engages cleanly without having to be pulled or pushed into position.

Traditional timber French doors may use a British Standard five-lever mortice lock with supplementary bolts, while many uPVC and aluminium doors use multi-point mechanisms and euro cylinders.

If the doors open outwards, add suitable hinge-side protection so exposed hinges do not become the weak point. If the patio door is also a regular escape route, keep the internal release simple enough to use quickly.

Bi-fold doors: keep the panels aligned

Bi-fold doors rely on several leaves, hinges, rollers and locking points working together. If one panel drops or the track moves out of alignment, the handle may still turn without every hook or shoot bolt engaging properly. Keep the track clean, check that the panels close flush and have stiff or dropped doors adjusted instead of forcing the lock.

When replacing older bi-folds, compare the security performance of the complete doorset rather than the cylinder alone. A strong lock is most useful when the frame, glazing and running gear are equally sound.

Upgrade the Locks, Glass and Frame Where They Matter

Once the door-specific weaknesses are dealt with, focus on the parts that decide how well the whole entrance resists force.

Choose a properly fitted euro cylinder where your door uses one

For uPVC or aluminium patio doors with a euro cylinder, West Yorkshire Police recommends a TS 007 3-star cylinder or a Sold Secure Diamond Standard (SS312) cylinder when upgrading.

The size matters too: the cylinder should sit flush with the handle or door furniture rather than projecting where it can be attacked.

If the door already has a multi-point mechanism, check that every hook or bolt engages when you lock it. Replacing the cylinder alone will not solve a dropped door, damaged keeps or a mechanism that no longer reaches the frame correctly.

Decide whether the glazing or complete doorset needs upgrading

Large glass panels are part of the security of the entrance, not just the view. Laminated glazing is designed to stay together when broken, while security film can help hold existing glass but does not automatically give the same tested performance as a rated laminated pane.

If the frame is loose, the door will not stay aligned or the locking system is unreliable, replacing the complete doorset may make more sense than adding several accessories.

Police.uk advises choosing security-accredited replacement doors tested to PAS 24:2022. If you are comparing higher-security patio doors, look at the tested performance of the complete door, frame, locks and fittings rather than one upgraded component.

Add Lighting, Alarms and Camera Coverage

Once the patio doors themselves are sound, make the approach easier to see and give yourself a useful alert when something happens.

Light the route to the patio

Place motion-activated lighting where it covers the doors and the route across the garden or side passage. A long or partly hidden approach may need more than one fitting. Aim lights so they illuminate the area without shining directly into the camera lens or neighbouring windows.

Use door contacts and cameras for different jobs

A door-contact alarm tells you when the door opens; a camera can show someone approaching beforehand.

Position an outdoor camera to cover the patio and garden route without letting the frame or nearby trees block the view. External mounting also avoids the night-time reflections that can affect cameras pointed through glass.

When choosing security cameras, check the night view, Wi-Fi signal, mounting angle, power supply and whether you need event clips or continuous footage. Aim them primarily at your own property. If the view extends into neighbours’ gardens, shared areas or the street, follow the ICO’s domestic CCTV guidance on proportionate coverage, signage and secure storage.

If the same side passage also leads to a detached outbuilding, our garage security guide covers the additional door and storage measures worth checking there.

Choose Camera Coverage That Matches Your Patio Layout

The best setup depends on where the patio sits and what power is available. A rear garden without a convenient mains connection may suit a solar camera, while a wired position above the doors can combine stronger lighting with continuous video.

SoloCam S340 for flexible garden coverage

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

Best for: Patios, side passages and garden approaches where a wire-free camera needs to cover more than one fixed angle.

• Dual-camera detail: A 3K wide-angle camera and 2K telephoto camera support 8x hybrid zoom, so you can keep the wider garden in view and inspect activity farther away.
• Pan-and-tilt coverage: 355° horizontal and 70° vertical movement helps one camera cover the doors and nearby paths.
• Solar-assisted power: The removable 2.2W solar panel supports normal battery operation when it receives suitable sunlight.
• Local storage: 8GB of built-in storage keeps motion-triggered clips locally without requiring a monthly storage subscription.

Floodlight Camera E340 for light and continuous patio video

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

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

• 2,000-lumen lighting: Two adjustable panels illuminate the patio, steps and surrounding approach when needed.
• Dual-camera monitoring: 3K and 2K cameras provide a 130° wide view plus telephoto detail, with 355° horizontal and 120° vertical movement.
• 24/7 local recording: Continuous video can be stored on a microSD card up to 128GB or through HomeBase S380.
• Hardwired power: The camera uses 100-240V AC, making it a better fit for a permanent powered position than a cable-free garden mount.

Video Doorbell S4 for complementary front-door coverage

A rear-patio camera cannot show visitors or deliveries at the front of the house. If you want coverage at both entrances, our Video Doorbell S4 adds a panoramic view of the doorstep alongside the patio setup.

Best for: Homes adding front-door visibility to an existing patio security setup.

• 180° x 180° panoramic view: The square field of view keeps visitors, parcels and more of the doorstep in one scene.
• 3K detail and tracking: 3K video works with OmniTrack AI tracking and auto-framing to follow a person moving across the entrance.
• Night-time visibility: Dual spotlights support colour night vision, while radar-assisted filtering helps reduce less relevant alerts.
• Wired monitoring: Continuous wired power supports 24/7 snapshot recording with 4GB of built-in local storage.

You can also compare our wider video doorbell range for different front-door layouts.

Conclusion

Effective patio door security starts with the way your own doors move and lock. Sliding doors need lift resistance 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 glazing is already weak, a tested replacement may offer more than another accessory. Once the entrance is physically sound, add lighting, alarms and camera coverage that match the garden approach.

FAQs

Should patio doors open inwards or outwards?

Sliding doors move sideways, so opening direction mainly matters for French and other hinged patio doors. Inward-opening doors normally keep conventional hinges inside, while outward-opening doors save indoor space but need secure hinge-side protection. Either arrangement can be secure when the locks, hinges and frame are designed to work together. The more important checks are whether both leaves close firmly, the locking points engage properly and the door remains easy to open from inside when needed.

Can I lock a sliding patio door from outside?

Yes, if the door is designed for external key access or can accept a compatible keyed handle or supplementary lock. Not every sliding system can be converted simply by changing the handle, so check the door design before drilling or replacing hardware. External locking also does not solve lifting on its own; the moving panel should remain secure in the track with suitable anti-lift protection.

Can you put a deadbolt on a sliding glass door?

A standard deadbolt made for a hinged door is usually not suitable. Sliding doors use purpose-made options such as key-operated patio locks, foot bolts, pin locks and fitted security bars. Choose hardware designed for the existing frame and position it where it does not interfere with the rollers or main lock. The best result is a secondary lock that adds another barrier while the anti-lift protection keeps the panel in its track.

When is it better to replace a patio door rather than add locks?

Replacement makes more sense when the frame is damaged, the door repeatedly falls out of alignment, the locking mechanism no longer engages reliably or the glazing and surrounding structure remain weak after repairs.

If the existing door is still sound, a correctly fitted lock, anti-lift device or glazing upgrade may be enough. If you replace the whole entrance, a PAS 24-tested complete doorset gives you a clearer security benchmark than adding a strong lock to a deteriorating frame.