How to anchor a safe to a weak floor?

I have to try to secure a safe so the bad guys don’t walk off with it, problem is that the floor is not at all secure enough to directly bolt it down. I need suggestions on what to do, and if you list exotic materials (i.e. road plates, depleted urnaium) also list where I can get them.

My thoughts are to attach it to something that would add lots of weight to it and make it physically very large.

Any suggestions?

More info, please? Wood floor? Concrete? House or business? What size is the safe?

More info, please? Wood floor? Concrete? House or business? What size is the safe?

Wood floor - no access under the floor, beams every 18 in, floor is carpeted over partical board.,

house ,

about 16 in square

Make that 16 in

So you can’t bolt the safe to the beams? Consider moving the safe elsewhere.

No access to under the floor makes it a bit tricky. Many wall and floor safes have mounting hardware that is accessed from inside the safe, the bolts going thru the safe’s walls and the studs/beams/joists. Obviously making removal of an unopened safe very difficult. Plus, they’re hidden, more or less, sometimes behind a picture or under a rug or whatever.

Other safes have external mounting hardware so you can bolt in to the floor or walls. Again tho, the bolts need to go thru the studs/joists to be secure.

If you mount a non hidden safe to the floor joists this way, even a weak floor becomes a formidable obstacle, requiring a fair bit of demo just to get the safe out of the house.
But with no under floor access? Let me think about this for a bit… Maybe someone else can jump in with ideas?

The safe does have the mounting hardware w/ bolts going throught the floor of the safe, but only at the diagnals (2 points)

Use a large upright gun safe. They weigh a lot and the weight will help to prevent it from “walking off”. If the stuff is that valuable a large safety deposit box would be a better investment.

Former bank equipment installer checking in-if that safe is merely sitting on a wood-framed floor, and my homework says there’s something inside that I want badly, I’ll remove that safe from the floor and haul it out, and there’s no physical means of attachment that can’t be compromised within 30 minutes. Being a good guy involves study of how the bad guys practice their craft. :wink: :smiley:

30 minutes is a very long time for a break-in, esp to work on one object.

I have considered taking some oak 2x4’s which could be mounted on the floor and attached to the floor beams to make a stronger base to mount the safe.

True enough, I included break time, considering union burglars.

Even with oak and grade 5 fasteners, the ultimate failure point will be the strength of the material in the floor and its resistance to fastener withdrawal, that material being the SYP or hem-fir joists, assuming you’re not on I-joists or lightweight trusses.

If there are bolt holes inside the safe, I would think that large toggle bolts would be sufficient. If the safe is not built into the (steel-reinforced concrete) walls, anyone with a chain and a truck can get it out, regardless what steps you take, but if you are simply trying to make it extremely difficult for the local corner thief to walk out with it on a dolly, the bolts should do it.

If you are concerned that someone with a sabre saw will simply remove the entire section of floor on which the safe sits, then you might want to consider welding some bar stock to the back of it that would make the section of floor to be cut too large to be practical (with the bar stock too wide to make it through a doorway).

Toggle bolts will work, as will lag screws. You can buy lag screws that are made in a one-way security configuration so they can’t be removed with a normal tool.

If you haven’t already purchased the safe, you might consider a fire safe. It took two guys one hell of an effort to get my empty two-drawer up to my loft. I thought one of them was going to stroke out. When full, it ain’t going anywhere. Of course, a good thief can drill it where it sits, so there’s that.

It is a fire safe, and it is heavy, but If I were going to break in I could manage the strength to carry it away.

Also I realize that any attachment I can make can be defeated, I am looking to detur the person who would rather go for eaiser stuff and really make someone who is determined to really work for it.

Pull up the carpet in the corner, pry up a board and put your valuables in the hole. Place the safe in a conspicuous spot with some bricks inside it.
Let hem spend their limited time working on loading the safe.

Locate the beams under the floor. Then use large lag screws, like ChefGuy mentioned, going from inside the safe thru the floor and into a beam. (If you can arrange it so they go into 2 different beams, even better.)

(Note that this may limit the placement of the safe, and make it more of a nuisance in the room. You likely can’t stick it into a corner, for example.)

If you use big enough lag screws, going deeply enough into those beams, it will prevent a quick & quiet theft of the whole safe. It won’t stop a really determined thief, but that doesn’t sound like what you are worried about.

I did, and still am considering that. Good thing no theifs ever read this board.

The problem is that the mountings will not span 2 beams, which is why I considered the oak 2x4’s. I guess I can mount it in the same beam with the safe at a angle

Particle board floor? Or do you mean OSB, oriented strand board, that’s often used as sheathing and subfloors, particle board is not.

A toggle bolt is very strong and should deter thieves. Not quite as strong as a lag bolt or long screw in solid wood. Of course, if you are not exactly centered in the floor joist with the lag bolt, you can have a very weak connection there instead.

That problem was mentioned on one of those This Old House shows, when they were putting in a shower grab bar. They used these grab bar wall anchors instead of going for the studs, to get a guaranteed strong anchor. Those anchors are designed to hold a person’s weight over and over again, on regular drywall, without ever failing, strong stuff. Put a couple of those under your safe, no way a thief walks away with it, unless they cut the whole floor apart.

I guess it’s OSB, I know it’s not plywood.

I can’t understand how those things are ment to hold on sheetrock, perhaps they would be more effective on floor materials.

I had another idea on how to do it and want to run it by you all:

I was considering bolting a 3 solid sheets of stong wood (or several if I can’t get one this big) to the floor, rear wall and corner wall respectivally, using some sort of tamper resistant bolts, with the bolts going into the floor and wall studs. Forming 3 sides of a box. Then I will mount the safe in that corner, tight against the side and back wall board, and bolt it down into the wood floor pannel, and if really lucky also into the floor stud.

Then I will use some smaller pieces of wood to ‘seal in’ the safe, and prevent getting a prybar directly behind it and leveraging it forward. The smaller pieces (perhaps 2x3) will go on top of the safe, bolted against the real pannel, on top bolted against the side wall, in the side bolted against the side pannel and floor.