How to Lock a Double Door: Securing French and Double Entry Doors
Published Date: Aug 15, 2025
Double entry doors are a popular feature in many homes and businesses across the U.S. They’re attractive, wide, and easy to use. Still, when it comes to safety, they often raise one common concern: how to lock a double door so it’s truly secure. Whether you’re dealing with French doors on your patio or double doors at your front entrance, getting the locking system right is key. This guide from Sure Lock & Key walks you through long-term hardware, short-term fixes, and smart solutions to match any double-door setup.
Understanding the Basics of Double Door Locks
In most double door setups, one panel stays fixed (the "inactive" leaf), and the other opens and closes (the "active" one). The inactive door is often secured with flush bolts or internal rods, while the active door carries the main lock. This system works, but if the fixed side isn’t locked securely, the entire entryway may be vulnerable.
The first step in learning how to lock a double door effectively is understanding how both panels function together. If there’s a gap, poor alignment, or outdated hardware, that connection weakens, making the door easier to force open. Before upgrading anything, it’s smart to explore how to choose locks for double doors based on the specific material and dimensions of your door.
Common Methods: How Do You Lock a Double Door Effectively
Let’s look at some of the most reliable ways to secure double doors. These options are widely used across both residential and commercial spaces:
- Flush Bolts: Mounted into the edge of the inactive door, usually top and bottom. Hidden when the door is closed.
- Mortise Locks: Durable, clean-looking locks recessed inside the active door — often used on high-end doors.
- Surface Bolts: Visible locking bolts attached to the surface of either door, easily added for extra security.
- Multipoint Locks: Locking systems that secure the door at multiple points along the frame.
- Smart Locks: Some smart models are now compatible with double doors and offer remote control via phone.
Each of these has pros and cons depending on how your doors are built and how often they’re used. Solid materials matter, too — wood, metal, or fiberglass all behave differently over time.
For similar entry types, like sliding or French-style patio doors, our guide on how to lock patio doors includes more helpful methods you might want to consider.
What If I Don’t Have a Lock? Simple Temporary Methods
Wondering how do you lock a double door if it doesn’t already have proper hardware — or if you’re a renter and can’t install anything permanent? There are safe, temporary options that still boost security:
- Slide Bolts: Affordable and easy to install on the inside of doors.
- Security Bars: Adjustable metal bars that block doors from opening inward. Great for patio doors.
- Pin Locks: Inserted through both door panels, stopping them from opening.
- Portable Door Jammers: Popular for renters and travelers, these add pressure against the door from the inside.
These are great for quick protection or extra reinforcement when locking your doors at night or before traveling.
When Locking Double Doors Goes Beyond DIY: Let a Locksmith Handle It
Some double door setups (especially older or custom-built ones) need more than a quick fix. Misaligned frames, outdated locking systems, or poor-quality installations can make it hard to secure both sides evenly. If your lock feels loose or if the doors don’t sit flush when closed, a skilled residential locksmith can diagnose the issue fast. Sure Lock & Key has years of experience working with double doors of all types — from historic French doors to new commercial setups. If your entryway needs a closer look, or you’re ready to upgrade without risking mistakes, our technicians are ready to help with honest recommendations and proven service.