Doors are an essential part of any property, providing security and privacy. They come in different sizes, shapes, and designs to match a building’s or room’s style and security needs. For example, most doors in a household have one lock, but why do some doors have two locks?
Double lock door knobs have two separate locks – a doorknob lock and a deadbolt. The doorknob lock is the round knob you twist to open or close the door, whereas the deadbolt is a separate mechanism that slides into the door frame when locked. Two locks are better than one, offering an extra security layer and peace.
If only one door has to have two locks in your house, it has to be your front door. But your backdoor may also need a double lock. This post should help you understand why some doors have two locks and how they improve security.
The Purpose of a Double Lock System
Do you know how to increase the security of a door lock?
The primary reason for having two locks on a door is to enhance security. Having a double lock system makes it harder for intruders to break into a building, as they would have to bypass two locking mechanisms instead of one.
All your exterior doors and entranced doors should have two locks to ensure proper security and prevent unauthorized access. In the case of a break-in, having two locks can slow down intruders, giving you more time to alert the authorities or escape.
Different Types of Double Locks
- Combination locks.
- Deadbolts.
- Door Knob locks.
- Keyed entry knobs.
- Electronic locks.
- Mortise locks.
How Different Double Locks Add Security on Your Door
1. Combination Locks
Combination locks are a type of keyless entry system. Their unique feature is that instead of using a physical key, they use specific numbers or symbol sequences to unlock the mechanism. Combination locks have been around for centuries and are still widely used today in various settings, such as:
- Schools.
- Gyms.
- Luggage bags.
- High-security facilities.
- Personal safes.
Combination locks are preferred for their reliability, affordability, and convenience. They’re composed of the dial, the shackle (or lock body), and the locking mechanism.
The dial is the round part on which numbers or symbols are displayed. The shackle is a U-shaped metal piece, and it secures the lock in place. The locking mechanism is hidden behind the shackle and unlocks it when you enter the correct code.
To set a combination lock, you must open and return it to its default settings. While still open, the user can turn the dial to reset the combination to their desired sequence. The new combination will then always lock and unlock it.
Combination locks can have different types of dials and locking mechanisms, but they all work on the same principle of matching a specific sequence of numbers or symbols to unlock the shackle. Some common types of dials include:
- Numeric dial locks have numbers from 0 to 9 displayed on them.
- Alphabetical dial locks display letters from A to Z.
- Multidirectional dial locks allow the user to enter the code by turning the dial in either direction, making it harder for someone to guess the correct sequence.
The locking mechanisms can also vary and may include:
- Single-dial mechanism: This type of lock has a single dial that must be turned to match the correct combination.
- Multiple-dial mechanism: These locks have multiple dials that must be aligned correctly to unlock the shackle.
2. Deadbolts
Deadbolts are another type of lock commonly used for securing doors. Unlike combination locks, deadbolts require a key to unlock them. They consist of a solid metal cylinder that extends into the door frame, making it difficult to force open the door from the outside. The three most common types of deadbolts are:
- Single-cylinder: This type has a keyhole on one side and a knob or lever on the other side.
- Double-cylinder: These have a keyhole on both sides, providing extra security but making it more difficult to exit in an emergency.
- Keyless digital: These use electronic codes instead of keys to unlock the bolt.
Aside from the type of locking mechanism, deadbolts also come in different grades based on their level of security and durability. The American National Standards Institute (ANSI) grades them three-way:
- Grade 1: These are the strongest and most durable, suitable for commercial and high-security residential use.
- Grade 2: These are mid-level locks commonly used in residential buildings.
- Grade 3: These are the most basic and affordable, best suited for low-security areas or as an additional lock.
3. Door Knob Locks
These are the most common lock types used in residential buildings. They consist of a doorknob with a mechanism inside that can be locked and unlocked using a key or by turning the knob itself.
These locks come in various grades and designs, but most operate similarly.
- Spring latch: It’s the simplest and least secure type of doorknob lock, where the latch automatically retracts when the knob is turned.
- Cylindrical: These have a cylinder mechanism instead of a spring latch, providing better security.
- Mortise: Similar to cylindrical locks, but with an additional bolt that extends into the door frame for extra strength.
Electronic door knob locks also exist. They require a keypad or touchscreen for entry, though you can also control them remotely via a smartphone app.
Door Knob locks are usually used in conjunction with deadbolts for added security. They are typically installed on interior doors, such as bedrooms and bathrooms, but can also be used on exterior doors.
4. Keyed Entry Knobs
Keyed entry knobs are another type of double lock frequently used in residential buildings. They operate similarly to doorknob locks but with the added feature of requiring a key for both locking and unlocking.
These locks vary in grade and design, with some offering extra features like an anti-pick mechanism or a reinforced strike plate.
One benefit of keyed entry knobs is that they can be rekeyed, meaning you can change the key without replacing the entire lock. This feature is useful when keys have been lost or stolen or when moving into a new home.
However, it’s important to note that these types of locks are easily picked or bumped, making them less secure than deadbolts.
5. Electronic Double Locks
Electronic double locks, alias electronic deadbolts, are growing more popular because of their convenience and extra security.
These locks use a keypad or touchscreen for entry, with some also offering keyless entry via a smartphone app. They typically have multiple access codes that can be programmed for different individuals, and some even have temporary codes that can be set to expire after some time.
One major advantage of electronic double locks is their ability to remotely lock and unlock doors. It suits them well for rental properties or busy households with frequent visitors.
However, these locks do require batteries and may not function during power outages. So, just how-secure are digital locks for doors?
Electronic double locks are also more expensive than traditional keyed locks. Overall, they offer a modern and convenient solution for double-locking doors.
6. Mortise Double Locks
Mortise double locks are the sturdiest and most secure type of double lock. They feature a heavy-duty lock mechanism that’s built into the actual door, rather than attached to it like other types of locks.
These locks often come with two deadbolts, one above the lock and one below, providing extra reinforcement against forced entry. They also require a key for both locking and unlocking, adding an extra layer of security.
One drawback of mortise double locks is their installation process, which can be more complicated and time-consuming than that of other types of locks. They also tend to be more expensive.
However, if security is your top priority, investing in a mortise double lock is worth the extra effort and cost. We recommend these locks for high-risk areas such as front entry doors or commercial properties.
Do I Need Two Locks on My Front Door?
Well, that’s for you to decide! It ultimately depends on your personal preferences and security needs. As discussed, there are various double-lock options, each with its benefits and drawbacks.
If you live in a low-crime area or have other security measures in place, one lock may be enough to provide adequate protection. However, if you want additional peace of mind or live in a high-risk area, adding a second lock can provide an added layer of security.
Additionally, having two locks on your front door also deters potential intruders. They may see the extra lock and choose to move on an easier target.
Ultimately, it’s important to assess your situation and decide.
Enhanced Convenience and Control
You don’t have to choose between convenience and security. At Kentucky Secured, we offer electronic double locks that provide the best of both worlds.
We hope you already know why you should buy a smart door lock for your home. By investing in a smart double lock, you can increase control over who enters your home. With remote access and temporary codes, you no longer have to worry about making copies of keys or leaving them under doormats.
Plus, we allow you to monitor and control your locks from your smartphone, making it always easier to keep your home secure.
