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Thread: Deadbolt Location

  1. #1
    Undead Pirate d_stilgar's Avatar
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    Default Deadbolt Location

    I've been listening to a lot of real estate investing podcasts lately. I listened to one where a guy said that he'll re-key his locks once a year because he does short term rentals (vacation properties). Someone asked him if he had considered using electronic deadbolts and electronic access (like a keypad, NFC, etc.). He responded that his biggest worry was having the batteries die on the system when he wasn't around.

    I started thinking of ways around this. One, obviously, would be to run power through the door via special hinges (available and relatively cheap). But I thought of another system that might be better. What if you just reversed the location of the lock? Usually the cylinder and deadbolt are in the door and the deadbolt extends into the door frame, but you could easily put it in the wall outside the door and have the deadbolt extend into the door itself. With electronic bolts you could even have several deadbolts around the door if you are really paranoid.

    I see an obvious limit to this right off the bat. If you have a limited approach from either side of the door (no wall around the door) then you really can't have something in the wall itself. I currently have this at my house since the door opens to a narrow hallway. But if you are going electronic, then you just need the lock to connect to a motor to move the deadbolt. The key doesn't need to be connected directly.

    The other issue with any of these systems is hacking. But every lock has its limits (and most are fairly weak), so this is just a different kind of weak, not necessarily weaker.

    Is there something I'm missing? Is is inherently weaker to have the cylinder and deadbolt located in the wall instead of the door?

  2. #2
    I got rid of my floppy disks Xpirate's Avatar
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    Default Re: Deadbolt Location

    I like that idea. But, I kind of doubt it will ever come. The lock in the wall would be strange for most people. Everyone is very used to having lock mechanisms in the door.

    I do not believe that setup would be weaker. It would also solve the problem of having to worry about batteries in a keyless lock. But, you would need a battery backup in the lock just like we have in smoke alarms that are connected to the AC power.

    A setup like that would be able to deadbolt all four corners of the door and make it really difficult to break through the door. I have seen a door break hinges instead of the reinforced deadbolt. It wasn't the exactly hinges that broke. The wood around them broke first. The side with the deadbolt had metal.

    I drilled a hole in my door for a peephole and discovered that my front door is not very strong at all. I think the inside of it is made of Styrofoam.

  3. #3
    Will YOU be ready when the zombies rise? x88x's Avatar
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    Default Re: Deadbolt Location

    Two problems I see with this:

    1) Manual override. Until electronic locks are a much more mature technology, people will always want manual overrides. This is why you see mechanical locks even on high security doors with expensive electronic locking systems. Also, emergency services may require this, I'm not sure. Think "how do I get this door open in an emergency if all power fails"?

    2) Maturity of the technology. There are a lot of electronic locks floating around on the market today that are really terrible. The problem is that a lot of them are lock companies making them with no background in information security. That's really the tough part; securing both the physical and electronic attack vectors.

    Now, that being said, the vast majority of residential locks are garbage anyway, so the later may not really be much of an issue. Besides which, the window is almost always going to be a much easier attack vector than the door.

    Looking at it from a convenience POV, though, another option would be to build an inductive charging system into the door, to couple it to the mains. That would at least obviate the worry of batteries dying while you are away.

    Quote Originally Posted by Xpirate View Post
    I drilled a hole in my door for a peephole and discovered that my front door is not very strong at all. I think the inside of it is made of Styrofoam.
    I assume this is a steel external door? Yes, the inside is a polystyrene foam. That being said, do not underestimate the strength of that steel shell.
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  4. #4
    Anodized. Again. Konrad's Avatar
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    Default Re: Deadbolt Location

    Electrical locks have always been available in powered-lock and powered-open versions.

    Local bylaws can impose restrictions on use, worries about safety egress during fires and power failures and such stuff.
    My mind says Technic, but my body says Duplo.

  5. #5
    Moderator TLHarrell's Avatar
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    Default Re: Deadbolt Location

    I have a deadbolt that I can instantly re-key using my key, a special tool, and a neighbor's key. It's pretty cool. Definitely the giant plate glass window next to the door is the weak link here. That, and numerous bricks around the front yard that can be used to instantly gain entry.

    As far as power to a deadbolt, use a door loop, hidden transfer which looks like a deeply mortised hinge with a wire inside, or just spring loaded contacts that touch when the door is closed.
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  6. #6
    Undead Pirate d_stilgar's Avatar
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    Default Re: Deadbolt Location

    Responding to issues:

    Manual override is a big issue with electronic locks now, and one that I personally take. It's one that isn't an issue if the lock is in a wall adjacent to the door (if it's an existing product with manual override), but would not be possible if there are several electronically triggered deadbolts around a door. The pro of electronic triggering is the possibility to have an electronic lock on a perpendicular wall to the door, since it is just sending the signal to the deadbolt. This also introduces the weakness of just manually applying voltage to the deadbolt mechanism without having a key/code to unlock the door. Pros and cons as far as I'm concerned.

    The technology is really young. Some of the issues I've seen with battery powered units is that the motor to close the deadbolt is usually underpowered. AC would fix this, whether routed through hinges into the door or in the wall. Battery backup is a must for power outages. The wall wins again with more flexibility and space in a wall than a door.

    Having the key in the wall would certainly be weird, but I don't think overly so. Cars have been doing a lot of weird things with keys over the past decade or so. Keys in dashboards. Keys that don't start the car but have a separate "Start" button. Flip-out keys. Electronic only keys. NFC keys. Wifi keys (Tesla). I think it's inevitable that we see this migration to our homes, and flexibility in the auto space shows that people can adapt.

    On the issue of lock laws, the IRC doesn't have much to say about the locks, other than people being able to unlock the door from the inside of their home. It's hard to say how that might be interpreted. Since locks have always been right on the door itself there's no precedent to compare this to. Any publicly accessible building has to have doors that swing out and have a panic bar if they are not unlatched anyway. Residential buildings are different since door almost always swing in (which I still don't understand) instead of out. So the answer is that it would have to be designed well, and would almost certainly have to start in single family since the regulations there are the most loose. A design solution (although unelegant) would be to have a switch in the shape of a padlock that would just trigger the padlock mechanism that's actually in the wall. It's still not as good as a manual override, but it addresses issues of interface confusion.

  7. #7
    Anodized. Again. Konrad's Avatar
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    Default Re: Deadbolt Location

    I guess popular wisdom is that a quality door, doorframe, and lock are more secure (resistant to forced entry, kicking/battering the door open) than exposed outswing hinges would be. Maybe it's a bylaw thing, cops and swats like to be able to dramatically bust a door down?
    My mind says Technic, but my body says Duplo.

  8. #8
    Undead Pirate d_stilgar's Avatar
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    Default Re: Deadbolt Location

    I've actually wondered that in the past. I even pitched it as a Mythbusters episode on their forums. I'd really like to know if the hinge resists forced entry better when the door is swinging in or out.

  9. #9
    Yuk it up Monkey Boy! Airbozo's Avatar
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    Default Re: Deadbolt Location

    I used to install electronic entry systems and have some knowledge of their installation and use.

    First there are codes related to commercial and residential locks that require the ability to evacuate from the premises either through a window or door. ALL codes require a person in a wheelchair to be able to exit a space unhindered (this is one reason there are manual over rides on residential electronic door locks). This means if the exit is to be a window, there must be a way for them to get out in their wheelchair. Not an easy task. Commercial codes also require access by emergency personnel so they can get in and rescue people or fight fires (etc.). Most counties will red tag a building if these restrictions are not met and in some cases they can impose heavy fines (usually only for commercial buildings).

    The codes also state that if the electronic lock is locked in a power fail state, that there must be a battery backup capable of powering the solenoid for a certain amount of activations or a specific duration of time. There must also be a manual activation switch located within a specific distance to the door and useable by someone who is handicapped.

    The codes also require specific wording of signs posted around such locks (I think this applies only to commercial buildings).

    With that out of the way, I do not see that having the locking mechanism in the wall instead of the door as being any less secure. In fact there are many card access systems that do just that. The major drawback is cost. Since the wall is usually at leas 8" thick in new construction (2x6 studs, drywall, siding etc,), you would have to have a deadbolt system with the appropriate length mechanism, including the securing screws. I have not seen one, but I would be surprised if they were not out there.

    Supposing you could find one, you would want a long throw bolt that extends into the door as far as possible and some sort of steel reinforcing plates on the door that would handle the stress of someone attempting to kick the door in, instead of putting the stress on the door.

    Here is one way to reinforce the door jamb in a normal deadbolt application (and what I use);
    http://www.asafehome.net/PAGES/Safe-...er-II-Pro.html

    I also have steel reinforcing plates in the hinge side of my door mounted under the jamb and special steel 6" screws in each hinge that go all the way into the 4 studs next to the door.

    Of course if anyone _wanted_ in my house, breaking a window would be the easiest way, but it would be hard to carry my tv through the window. A door lock is not intended to prevent anyone from gaining entry, just to slow them down and make it noticeable or very noisy.

    I found some pretty interesting things while doing a google search on wall deadbolts;

    http://villedoors.com/stainless-stee...ron-entry-door

    Last edited by Airbozo; 04-24-2015 at 03:15 PM.
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  10. #10
    Anodized. Again. Konrad's Avatar
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    Default Re: Deadbolt Location

    Thieves might gain entry through a small window, wall cutout, escape tunnel, whatever.

    But once they're inside, they can just unlock a door and walk out. With your bulky TV, if they like.
    My mind says Technic, but my body says Duplo.

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