safe on a concrete floor

[sonora]

How do you know all this stuff?

 

[CapnMac]

How do you know all this stuff?

About 40 years' in the architecture & construction biz as a "day job."
So, I've poured foundations, and framed buildings, along with writing the specifications & plans to build them. Renovated/repaired more than my fair share, too.

Almost as second-nature as sight alignment, or the fit of a 1911 in my hand. (Ok, my work computer has tabs always open to 2012, 2015, 2018, and 2022 IBC, too, as references--much as folk have multiple reloading manuals to hand.)

 

[mjsdwash]

just like to add to the elevated block idea, that is a huge advantage in a flood.

 

[CapnMac]

just like to add to the elevated block idea, that is a huge advantage in a flood.

Pressure-treated lumber is your go-to in that case. Which could be as simple are four 4x4 on end in a 2x box frame to keep the 4x4 stable, vertically.
SYP/F (Southern Yellow Pine/Fir) 4x4 will support 3000# easily. An 800# safe on four supports is only 200# per each; ciphering it out, it's only 16psi, an easy load for 3-4" of well-placed concrete.

Image is scaled to 36 x 30 x 11.25" (2x12)
A person might want a sheet of plywood over top, but it will be exciting enough getting the bolt holes marked through as is. Like as not, using all thread epoxied into the slab would be the efficient thing set up like this.

 

[Pulldeaux]

Had my sons large Liberty in the garage for several years. Had it on a pallet with no issues. Finally moved it to his home, no signs of rust , corrosion or anything.View attachment 1057999

Peace of mind

 

[plainsdrifter]

CapnMac is right. Im a flooring contractor/inspector and do moisture testing of concrete all the time.
Rubber should be closed cell.
The only other film commonly used under floating floors that has a better perm rating than 6 mil plastic is 2 mil foil believe it or not.

 

[74man]

I made a cradle out of 2" x 2" angle iron and put casters on the corners which swivel so in case of fire it can be rolled out of the garage to safety. It weighs 600 lbs. and my garage is not easy to get into. I would put it on blocks of wood and the bolt it down using anchors.

 

[doubleh]

I have one in the garage that has been there for years, metal on concrete, with no problem at all. Of course the concrete floor had been curing for years before the safe was placed and the only way we have much humidity is with a swamp cooler of which there isn't one to affect it. If I were unfortunate enough to live where there is constant high humidity or new concrete I would use plastic under it.

 

[Maver1ck]

I had no idea a rubber mat would help with safe installation. Will be buying one for my next safe purchase. Thank you!

 

[johnjohn]

My safe sits on 4x4 lumber,air can flow around it. SE La. humidity,no problem.

 

[jmorris]

Getting a new safe pretty soon and will be bolting it down to a concrete floor .

Have heard it might be a good idea to put something under the safe but what a rubber mat ?

I have carpet or wood flooring under them but I think being in a climate controlled environment is more important that sitting on something.

 

[Walkalong]

I have carpet or wood flooring under them but I think being in a climate controlled environment is more important that sitting on something.

Agreed.

I moved last year, safe had been sitting on carpet for 30ish years in a climate controlled house, no issues under it.

Concrete will hold and pass water, best to have something under it, raised is a plus, but then again, if you move it in 20 years and it has a touch of rust underneath, has it/will it, hurt anything?

Bolt holes are a path for moisture into the safe, so again, a barrier, or raised with a barrier. Plug them or use them, but they can still pass water vapor.