Hello from China

[Chubby]

I am new here. I have been fascinated by locks for as long as I can remember!

Do we have anybody with good knowledge of strongroom construction? I have a house in Europe in which I am going to construct a small strongroom. I think I have sourced a Chubb 12mm door. The floor will be a straight pour of readymix. The walls are a bit of a problem. The local bricks are very soft. So I intend to ignore those in calculating the requirements for the walls. They are just an added barrier. I propose to line them with some steel plate. I am not sure quite what the thickness will be. Probably 5mm or so. That will be anchored to the inside of the soft walls in individual pieces and I shall, then, weld the sheets together. I am a fairly competent welder. Then inside the steel box I shall use standard high density concrete blocks but lay them on their side so I get about 9" of concrete. Would that be adequate? To make the opening for the door I might go a bit thicker and build the uprights, then probably get a precast lintel the length of the entire wall and cement that into place. The roof will be 3 x 3 concrete fence posts. (I have dozens) spanning wall to wall and then another readymix pour on top of that. Plenty of reinforcing mesh in it of course.

I have also sourced a fairly heavy safe. The door and frame are very good but the back and sides leave much to be desired. Rather than use a pallet I have asked the supplier to weld a couple of pieces of I beam to the underside so I can get my pallet truck in. I will move the safe to the back wall of the strongroom and cast a plinth around the I beams. I shall then brick it in and back fill with high aggregate concrete. I will add a steel skin to that wall, although with that much concrete in front it should scarcely need it! The idea is to keep the concrete off the brick work to prevent the concrete from cracking the bricks. I suppose a sheet of polythene would do equally well. Again opinions please.

[Dean Nickel]

Concrete comes in many different mixes. If you get the type that is used in shop floors for heavy equipment and set it with a good deal of re-bar it will be hard to get through. I can tell you as I had to spend hours trying to install a safe in a floor of a Caterpillar dealer and that was using a commercial jack hammer. It had very little stone it it... it just powder not crack.

Now I know many safe companies sell vaults that are assembled on site if you want better protection. But if you just put that concrete around your safe the door is the only weak point really.

[Chubby]

A vault assembled on site would be too expensive. I am going to build out of fairly standard construction materials. It has to fit inside an existing room.

I have an excellent recipe for concrete which dries harder than a mother in law's heart.

[Tom Gordon]

That seems to be fairly effective against many attacks and I dont want you to post here the value of the contents, but the contents are what determine how good a vault you need.
For higher risks I would suggest that concrete blocks do not provide the structural integrity of reinforced concrete.

[Chubby]

It horrifies me the details that people post on a public forum. I don't doubt that criminals use the information available!

The only issue now under consideration is whether to use the solid blocks or the hollow ones and pour into the voids.