Double-cylinder locks?

[ChemicalRobot]

I'm very new to lock picking and I was wondering if someone could enlighten me on how a double-cylinder deadbolt is different from a normal one. I've tried searching around but I haven't come across a good explanation.

[ChemicalRobot]

I'm very new and don't know terminology too well.

[yng_pick]

Double cylinder, or double sided, means keyed on both sides.

For instance-
If a deadbolt has a keyed lock on the outside and a thumbturn on the inside, it is single cylinder.

If it is keyed on both sides, it is double cylinder/sided.

[ChemicalRobot]

Double cylinder, or double sided, means keyed on both sides.

Great! Thanks for the help, yng_pick. I had figured this was what it was, but I felt it best to ask anyways to make sure I wasn't getting definitions mixed up.

[loki-aka]

By the way, double cyl deadbolts are not allowed by code in some towns and cities (maybe state wide). Though the presence of such laws does not preclude some stores from selling them.

[pjzstones]

By the way, double cyl deadbolts are not allowed by code in some towns and cities (maybe state wide). Though the presence of such laws does not preclude some stores from selling them.

i find that really wierd. do you know why?

[yng_pick]

Fire code; idea being that in a fire having to rely on finding a key to get open your deadbolt and escape is dangerous.

Similarly, on emergency exits/ doors with pushbars, a deadbolt cannot be used on commercial buildings in my area.

[globallockytoo]

By the way, double cyl deadbolts are not allowed by code in some towns and cities (maybe state wide). Though the presence of such laws does not preclude some stores from selling them.

This is not true!


The international building code is the code used by all localities and can only be modified by the local AHJ (Authority Having Jurisdiction), usually the local fire marshal.

The code reads, Primary entrance doors are required to be single cylinder function.

Double cylinder locks can still be legal to use on doors like patio doors, basement walkouts (as long as it is not considered a primary entrance or exit).

Many patio doors are wood/aluminum framed with large glass panels. If the door is not considered primary, then you can still use double cylinder products.

[eppiotic]

You just need single motion egress.

[loki-aka]

Yes. You guys are right about double cyl. permitted on some doors- typically non main exit nor emergency egress doors. Thanks for noting the exceptions.

[MacGnG1]

double sided deadbolts are WONDERFUL for practice!!! you can keep one side keyed to the original key and then rekey the other deadbolt. and the good thing is that the double deadbolt usually only costs a bit more than it's single sided counterpart. have fun

[Evan]

By the way, double cyl deadbolts are not allowed by code in some towns and cities (maybe state wide). Though the presence of such laws does not preclude some stores from selling them.

This is not true!


The international building code is the code used by all localities and can only be modified by the local AHJ (Authority Having Jurisdiction), usually the local fire marshal.

The code reads, Primary entrance doors are required to be single cylinder function.

Double cylinder locks can still be legal to use on doors like patio doors, basement walkouts (as long as it is not considered a primary entrance or exit).

Many patio doors are wood/aluminum framed with large glass panels. If the door is not considered primary, then you can still use double cylinder products.

What is considered the "primary" door along an egress path from any given room can include many of those other doors besides the house's main front entry door...

That is why you should consult your local AHJ before installing one... Installing double cylinder locks on your door can cause drastic issues with your insurance company in the event of a loss and your failure to inform them of the installation of such locks on your premises...

~~ Evan

[Squelchtone]

In my neck of the woods, word on the street is that you can have a double deadbolt on your door, but if you are in the domicile and the deadbolt is locked, you have to keep the key inside the lock to act as a thumb turn. If you are leaving for the day to go to work you can remove this key, so a burglar cannot simply break the glass and reach in and turn the thumb turn or the key you left there.

At my old house, I kept a key hanging on a nail around the corner so on my way to egress, I would always know it was there and could grab it while heading towards the door in case of emergency. It was a double cylinder Medeco, and I slept better not keeping the key inside the lock for use as a thumb turn. I think it's a matter of choice, even if the local fire codes do not allow for such installation or use. The rules exist because someone probably died in a fire, because they couldn't find their keys in the smoke. I'd like to think I don't fall in that group.

Squelchtone

[Evan]

In my neck of the woods, word on the street is that you can have a double deadbolt on your door, but if you are in the domicile and the deadbolt is locked, you have to keep the key inside the lock to act as a thumb turn. If you are leaving for the day to go to work you can remove this key, so a burglar cannot simply break the glass and reach in and turn the thumb turn or the key you left there.

At my old house, I kept a key hanging on a nail around the corner so on my way to egress, I would always know it was there and could grab it while heading towards the door in case of emergency. It was a double cylinder Medeco, and I slept better not keeping the key inside the lock for use as a thumb turn. I think it's a matter of choice, even if the local fire codes do not allow for such installation or use. The rules exist because someone probably died in a fire, because they couldn't find their keys in the smoke. I'd like to think I don't fall in that group.

Squelchtone

Squelchtone:

Maybe not you, but say your bedroom is upstairs and the fire that breaks out cuts you off from coming down the stairs and you have to evacuate by means of some other route...

Let's say that terrible night is the night that you have an overnight guest sleeping on the couch in your family room on the first floor who in a panic tries to escape through the front door and doesn't know where the little hook for your key is on the wall near the door... Maybe they live long enough in the smoke to be rescued when the fire department bashes the door clean off its hinges to make entry and maybe they don't... By the time they wake up (if they even do) they have been breathing in the smoke for a while already...

You really want to have to ever be in a position to survive a fire in your home while a visiting guest or one of your children doesn't... Feel however you want with a double cylinder door lock installed, hide the key wherever you want to... It won't stop a thief from breaking a window on your house to steal stuff from you, it only makes it slightly more difficult for them to carry your stuff away...

Double cylinder locks won't protect your house as well as a properly designed and monitored alarm system will... And the alarm system can do other wonderful things like being tied into your smoke and CO detectors to save your life in the middle of the night and water sensors in the basement in case a pipe bursts while you are not at home...

If you still think it is a matter of choice even if local codes don't allow for it, you had better install automatic fire sprinklers in your home because if anyone was ever injured in a fire at your home and a double cylinder lock was found to be on the primary egress door, you would be dealing with a criminal charge of at least reckless endangerment if nobody was seriously hurt up to negligent homicide if someone died...

~~ Evan

[Squelchtone]

If you still think it is a matter of choice even if local codes don't allow for it, you had better install automatic fire sprinklers in your home because if anyone was ever injured in a fire at your home and a double cylinder lock was found to be on the primary egress door, you would be dealing with a criminal charge of at least reckless endangerment if nobody was seriously hurt up to negligent homicide if someone died...

~~ Evan

wow... why don't you tell me how you REALLY feel..

I lived in that house by my self, it was a 1 floor dwelling, and when I did have people over, I would leave the key in the door because I know not all people are used to double cylinder deadbolts. Sometimes, when my gf would spend the night, I wouldn't even lock the deadbolt, just the lower knob. Don't worry, I already covered all the bases, and considered all the outcomes of my decisions.

I also happen to install wiring in people's walls for a living, I think about life safety all the time. And I do a good job because I would feel very guilty if I ever wired something that led to a house fire where people died or a business lost it's offices or assets.

Squelchtone