Can a Mechanical Stopper Protect My Apartment Door from Intruders?

[chirhone]

I rented a unit at the 32th floor for 6 months. The door has only 2 locks. The top has a double lock. The bottom is a normal door lock.

Now imagine a drunkard or robber that would just kick the door from outside. It is enough to break the lock as it's secure on just wooden frame.

Do you know of any mechanical device that you can put on the inside (kind of shim put at bottom) so even if the drunkard kick it many times. The door is still secured? The portable device has to be something that doesn't require drilling of the concrete (as I just rented the unit).

Thanks.

 

[Lnewqban]

 

[chirhone]

View attachment 257415

Thanks. What do you call it exactly? When I tried to google "door stopper". I got another product, one that stops door from hitting wall when you open it.

I assume it is screw on and not hydraulic powered. But with a small pump beneath. It can be hydraulic.

 

[AZFIREBALL]

Get two of these. Put one at the top and one at the bottom of the door. He will need to tear out the door frame to get in. Simple but safe.

 

[berkeman]

Do you know of any mechanical device that you can put on the inside (kind of shim put at bottom) so even if the drunkard kick it many times. The door is still secured? The portable device has to be something that doesn't require drilling of the concrete (as I just rented the unit).

Do a Google search like this:

But keep in mind that the more you secure your door, the longer it will take EMS and the police to get into help you if you or your family call for emergency help. Be well.

 

[chirhone]

Get two of these. Put one at the top and one at the bottom of the door. He will need to tear out the door frame to get in. Simple but safe.
View attachment 257416

Are the screw parts on the door or floor? How is it supposed to stop the door from opening mechanically?

Ill look into your link Berkeman.

I need one where even if the drunkard where to step 10 meters backward and run very fast into the door. It still won't break. And only axes or sledgehammer can break it so enough time to hear it and call 911.

 

[berkeman]

To be honest, I think you are being a bit paranoid here. How often does that type of crime happen in that building?

 

[chirhone]

To be honest, I think you are being a bit paranoid here. How often does that type of crime happen in that building?

My original home has security guard. In our temporary condominium building with a thousand units. The guards are only in the lobby. And one can never predict. The problem with the building is that security is poor. Anything can get up to any units. Unlike other more secure buildings.

 

[Rive]

The top has a double lock. The bottom is a normal door lock.
... it's secure on just wooden frame.

Maybe worth a second checking on that. I've seen many cost-effective things already, but locks usually expected to be 'locked' into the wall and the frame is just a decoration.

 

[Lnewqban]

Thanks. What do you call it exactly? When I tried to google "door stopper". I got another product, one that stops door from hitting wall when you open it.

I assume it is screw on and not hydraulic powered. But with a small pump beneath. It can be hydraulic.

Look up "security bar door jammer".
No screws at all, bottom works based on friction.

I have been using one of those, not sure if a drunk guy has tested it yet, though.
Really feel sorry for that guy if he tries when we are out and the bar is not installed, he will not find much inside my apartment.

For any better deterrent, you must use screws.

 

[AZFIREBALL]

Are the screw parts on the door or floor? How is it supposed to stop the door from opening mechanically?

Ill look into your link Berkeman.

I need one where even if the drunkard where to step 10 meters backward and run very fast into the door. It still won't break. And only axes or sledgehammer can break it so enough time to hear it and call 911.

This device requires two screws to be placed in the door frame in the gap between the door edge and the frame. then the flap is raised up and rotated 90 degrees and dropped in place to block the door from opening. Very effective.
BTW- What city do you live in?

 

[chirhone]

This device requires two screws to be placed in the door frame in the gap between the door edge and the frame. then the flap is raised up and rotated 90 degrees and dropped in place to block the door from opening. Very effective.
BTW- What city do you live in?

Quezon City.

https://www.rappler.com/nation/127860-quezon-city-pnp-highest-index-crime

I still can't imagine how your device is connected. I checked others based on berkeman keywords. I found this:

The above works because it's pushing against the fixed hole in the floor. What is yours pushing against? Please show some link how it works. I need to buy two different kinds of protection to be sure the door is not kickable without making loud noises enough to call 911.

 

[Janus]

Are the screw parts on the door or floor? How is it supposed to stop the door from opening mechanically?

Ill look into your link Berkeman.

I need one where even if the drunkard where to step 10 meters backward and run very fast into the door. It still won't break. And only axes or sledgehammer can break it so enough time to hear it and call 911.

 

[anorlunda]

That door flip lock should work, and you could fill in the screw holes if you leave the apartment.

But I would not recommend a door with a big window like in the video, nor a flimsy door that a drunk could put his foot through.

 

[chirhone]

Im stll trying to find source for it.

So far this is the only one i found at china via lazada.

Will it work? Based on similar config in your experience?

 

[Lnewqban]

... Will it work? Based on similar config in your experience?

That device will not prevent your seriously determined guy (reaching the 32th floor, stepping 10 meters backward and running very fast onto the door) to break the two regular locks, because the door is flexible and those are located higher, by the area of impact.

Please, see:
https://yourhomesecuritywatch.com/review-best-door-security-bars/

Wouldn't be easier for that guy to wait until nobody is home or until you are leaving or arriving to your apartment?

 

[AZFIREBALL]

Are you allowed to have a weapon in the house?

 

[Janus]

Another option is to replace the lock plate for the dead bolt with a more secure option like this:

It's sturdier, and the longer screws reach all the way into the wall stud.
Of course, you would have to clear it with the landlord first, and leave it behind when you move.

 

[Tom.G]

You mention that the door frame is just light-weight wood set into a hole in the concrete wall. You want to secure the door with better locks.

With that construction, you have the same problem with the hinges breaking out the door frame.

Also, if you floor-mount a stop/lock as in posts #12 or #15, that still leaves the existing locks and upper hinges vulnerable. The floor-mount stop/lock will just be a pivot point.

For real security at least three, preferably four, restraints are needed: a high and low placement on the door edge with the locks, and at least one on the edge with the hinges.

The approach in post #2 is probably the easiest and is quite effective. That bar from the doorknob to the floor is adjustable in overall length, either by threads cut into the two telescoping pieces, or steel pin(s) inserted in holes to fix the length. They work well on solid floors, not so well on carpets. To lock, you just wedge them in by kicking them in place.

Using another of those bars at the hinged edge would make for rather good security. Since there is no doorknob at that door edge, screw a length of good-sized angle iron to the door horizontally across the solid part of the door. Use several large diameter screws. Several large screws because the inward force by an attacker is translated to an upward force that trys to rotate the angle iron upward, pulling the screws out.

Of course the landlord will want to charge you for a new door when you move out... unless you fill the holes and do a decent paint job.

The above will keep the door closed but that won't stop someone from kicking in the lower door panel. You could attach a steel plate over the lower half of the door... if you don't mind the place looking like a prison.

Or just replace the whole thing with a metal door with a separate heavy bar across it. The bar would drop into sturdy hooks firmly attached to the concrete wall on either side of the door. That would likely cost several months rent, and a VERY mad landlord though!

Let us know what you decide on.

Cheers,
Tom

 

[chirhone]

You mention that the door frame is just light-weight wood set into a hole in the concrete wall. You want to secure the door with better locks.

With that construction, you have the same problem with the hinges breaking out the door frame.

Also, if you floor-mount a stop/lock as in posts #12 or #15, that still leaves the existing locks and upper hinges vulnerable. The floor-mount stop/lock will just be a pivot point.

For real security at least three, preferably four, restraints are needed: a high and low placement on the door edge with the locks, and at least one on the edge with the hinges.

The approach in post #2 is probably the easiest and is quite effective. That bar from the doorknob to the floor is adjustable in overall length, either by threads cut into the two telescoping pieces, or steel pin(s) inserted in holes to fix the length. They work well on solid floors, not so well on carpets. To lock, you just wedge them in by kicking them in place.

For start. I'd love to get this bar shown in post #2.. but watch the second review video in amazon by Y. King...


It fails easily.

Here is a more mil-spec version that is priced 5 times higher, but it can slide (read the critical review).

https://www.amazon.com/dp/B002BQ4VBU/?tag=pfamazon01-20

What door bar or stopper does the military or M15 agents used to secure themselves at night in a hotel room?

Using another of those bars at the hinged edge would make for rather good security. Since there is no doorknob at that door edge, screw a length of good-sized angle iron to the door horizontally across the solid part of the door. Use several large diameter screws. Several large screws because the inward force by an attacker is translated to an upward force that trys to rotate the angle iron upward, pulling the screws out.

Of course the landlord will want to charge you for a new door when you move out... unless you fill the holes and do a decent paint job.

The above will keep the door closed but that won't stop someone from kicking in the lower door panel. You could attach a steel plate over the lower half of the door... if you don't mind the place looking like a prison.

Or just replace the whole thing with a metal door with a separate heavy bar across it. The bar would drop into sturdy hooks firmly attached to the concrete wall on either side of the door. That would likely cost several months rent, and a VERY mad landlord though!

Let us know what you decide on.

Cheers,
Tom

 

[chirhone]

Are you allowed to have a weapon in the house?

The apartment is only one room and 50 sq. mtr or less. If the intruder gets in. I don't have time to open the vault/safe and get the gun. And one can't just tuck the gun under the pillow. And I don't own a gun.

Just want something that will take at least 2 minutes to break the door so can dial emergency.

About what to steal. Imagine someone at the lobby saw amazon delivered your new laptop. The robber can aim for the laptop. Or imagine your partner looks like Hailee Steinfeld, etc.

 

[chirhone]

Get two of these. Put one at the top and one at the bottom of the door. He will need to tear out the door frame to get in. Simple but safe.
View attachment 257416

Has anyone actually used this? I read this is only very effective to keep toddlers in the house.
"
Q: Is this lock good for keeping out strangers from getting in our home from outside doors

A: No. Someone could kick this lock open pretty easily. We use them on inside doors for child-proofing purposes i.e., locking door to basement so our toddler can't pull the door open and fall down the stairs.


A: I doubt this would be good for keeping strangers out. It might be a BIT of a deterrent, but would probably be broken through easily if they really wanted to get in. It's much better for keeping your kids from opening doors they shouldn't. Hope this helps!

"
Q: Is this strong enough to keep someone kicking the door open?

A: No, definitely not. It would rip out of the door frame with enough force."

And

"
Q: Are these strong enough to keep burglars away? e.g. if I place 3 on each door?

A: They are strong and would require a decent amount of force to bust through. But I wouldn’t rely on these to keep a determined burglar out. You can also only use these when you are inside the door - they cannot be locked or unlocked from the outside so in essence they really only function when you are home."

https://www.amazon.com/dp/B001LR1YA6/?tag=pfamazon01-20

 

[AZFIREBALL]

Another idea:

 

[chirhone]

After much considerations, i ordered the most expensive Buddybar Door Bar to avoid breaks of the bar parts. Its strong enough to lift a car (do not try this at home).

But the bar has tendency to slip in some floors. I still ordered it to try. If it slips. Ill get this.

This is about 135 lbs actually built i saw in net. I heard it has good staying behavior. How do you compute what must be its weight so the door bar won't slip?

 

[Tom.G]

But the bar has tendency to slip in some floors. I still ordered it to try. If it slips. Ill get this.

Th closer to vertical the bar is set, the less likely it is to slip... up to a point. If actually vertical it won't be of much use at all. The optimum angle depends on the coefficient of friction between the floor and the material of the foot of the bar. Polished concrete and tile floors are the most problematic, with carpets a close second. Best seem to be wood or vinyl floors, something with decent friction and a small amount of compressibility. That suggests a block of wood under the foot of the bar may help on hard flooring, but I haven't tried it.

Sounds like some experimenting is in order.

Cheers,
Tom

 

[chirhone]

Th closer to vertical the bar is set, the less likely it is to slip... up to a point. If actually vertical it won't be of much use at all. The optimum angle depends on the coefficient of friction between the floor and the material of the foot of the bar. Polished concrete and tile floors are the most problematic, with carpets a close second. Best seem to be wood or vinyl floors, something with decent friction and a small amount of compressibility. That suggests a block of wood under the foot of the bar may help on hard flooring, but I haven't tried it.

Sounds like some experimenting is in order.

Cheers,
Tom

The distance between my knob and floor is about 39 inches. Whats yours and the common in the US?

 

[Tom.G]

Don't know about the 'common', where I live the measured interior knob height is 35½-36 in. and the exterior is 39½.

 

[chirhone]

Don't know about the 'common', where I live the measured interior knob height is 35½-36 in. and the exterior is 39½.

Why is it not the same height exterior and interior when it is made of the same lock (bottom of picture)??

 

[chirhone]

Why is it not the same height exterior and interior when it is made of the same lock (bottom of picture)??

View attachment 257580

This is also why the door flips won't work. Because imagine the door frame lock holes were shred as the door is kicked open. All the door flips would just go off along with the main lock holes. Objections? Affirmations? This is why the door bar along with a heavy object fixed is more secured (I think).

 

[gary350]

Once I bought a long 2"x4" board cut it to fit between the door and the opposite wall. Simply lay it on the floor no one can kick the door in. Door locks only keep out honest people. Thief with, ax, chain saw, pry bar, 10 lb hammer will get in.

 

[chirhone]

Hope this will work (8 pounds steel):

My concern is what if someone would just insert a tiny long blade from outside and push the bottom?

What mechanical principle would prevent that?

Any alarm that would trigger off when someone tries to insert something in the floor gap? And how do you secure the floor gap?

 

[chirhone]

This works. My friend couldn't open the door from outside. But I wasn't able to test it by him pushing very hard on the door or running into the door. Would the testing damage the door?

Next to arrive would be the 8 pound all steel door bar. Again I don't know how to test them without damaging the door I just rented.

 

[gmax137]

But I wasn't able to test it by him pushing very hard on the door or running into the door. Would the testing damage the door?

Quite possible to inflict damage on the door.

 

[chirhone]

This 8-lb door bar works better than the tiny one, but what would stop a person from inserting something flat at the bottom gap to push it? Is there a mechanical gap filler of some kind you can install too that can't be moved from outside?

I hope robbers don't read physics forums and learn about my devices.

 

[Rolacycle]

Start looking for an apartment with steel framed door. Most braces won’t stand up to this

 

[chirhone]

I still have 3 months of rent left (I may leave early though if COVID-19 transmission is confirmed).

I want to take this opportunity to learn mechanical principles and create a competent defence capability.

In the picture above. Would it be better to get a pole (shown in orange line) to brace against the door bar, or would it be better to put the orange pole directly on the door (without any door bar, I can sell it)? But what would prevent the orange pole from sliding if it is put directly on the door? I can't put any screws or alter the door in any way.

This is the full perspective, and another option:

I can put two poles and a metal plate brace against the door. But how do you design it such that you can disassemble and assemble it easily? without creating a solid welded connection that you would have difficulty removing in the day?

 

[gmax137]

But how do you design it such that you can disassemble and assemble it easily?

Truckers use "load bars" inside the trailer. These are adjustable-length cam-lock devises. Maybe you could put one pad against the door, and the other against your interior door frame. Once the length is adjusted, you just squeeze the lever to extend the pad a little bit to create the tension.

https://www.amazon.com/slp/load-bars/apr3amdx7tquuv6&tag=pfamazon01-20

 

[chirhone]

Truckers use "load bars" inside the trailer. These are adjustable-length cam-lock devises. Maybe you could put one pad against the door, and the other against your interior door frame. Once the length is adjusted, you just squeeze the lever to extend the pad a little bit to create the tension.

https://www.amazon.com/slp/load-bars/apr3amdx7tquuv6&tag=pfamazon01-20

Before I order these load bars (note your url is wrong). I'd like to know if anyone owns one. How strong is it when pressed from the longitudinal side or axis (or when the door is pushed against it)? Remember it is designed for side restraint.

Meanwhile I have temporary solution.

I'd like to compute it. Say a person of 160 lbs run into the door from 10 meters away. What is the force of impact. What units do you use? Joules or KiloNewton? And what Joules/KiloNewton before the door hinges and bar would yield? Can someone give a sample computation? And all formulas involved?

Thank you.

 

[some bloke]

If you're worried about people shoulder-barging the door, then you could always hammer some nails through it from your side. Just so they poke through a little.

They won't do it twice.

 

[rama3njoy]

there is grove in the middle door, make brace with 2x4 wood, add rubber on the wood witch make contact with floors