Deadbolt locks are by far the most popular type of lock for Canadian homes. There’s something about having a solid steel bar between your door and the door jamb that instills a sense of security for homeowners.

Among other variations, deadbolts come in single- and double-cylinder configurations. But you’d be mistaken to think that the “double” provides any more protection than the “single”.

A double-cylinder deadbolt doesn’t have a second deadbolt. The “double” refers to the fact that a key is required to open the door from both the outside and the inside. If you had one on your home or office door, you would need a key to open the door when you leave for the day, and a key to lock it behind you after you leave.

Why would anyone want to have to use a key twice instead of just once? If your door has a glass panel or is situated beside a window, a double-cylinder deadbolt will prevent someone breaking the glass to reach in and open the door.

On the other end of the spectrum, double-cylinders could pose a safety risk. If the door is locked when you are inside, you will need the key to get out in a hurry. If there is an emergency, like a fire or other urgent reason to get out of the house, you will use up valuable time to insert the key, turn the lock and open the door.

Needless to say, the results could be disastrous if you can’t find the key or have any trouble negotiating the lock.

With little or no difference in how secure they are against unwanted entry, the choice of whether you use a single- or double-cylinder deadbolt in entirely up to you.