safe on a concrete floor

[flatsticks]

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 ?

Figured it needs to be fairy thin so the safe is bolted down and not a lof of space under it .

The humidity in that room is never high between 33 ( winter ) and 45 ( summer ) percent all year long..

Appreciate your thoughts and ideas

 

[berettaprofessor]

I used a really thin plastic sheet that was from a skid package....so the size of a 4X4 skid and about 3 mm's thick.

 

[CapnMac]

Contact a flooring supply house and see if they have a remnant of vinyl sheet flooring about the size of your safe.

Some 6 mil (0.006") plastic sheeting ought to keep moisture in the concrete away from the metal bottom of the safe. Trouble being you probably don't need the whole 600 square feet of a whole roll of it.

The other option would be a scrap bit of TPO or EPDM roofing, which would also keep the moisture away.

 

[Big Wes]

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.

 

[FAS1]

A thick rubber horse stall mat is commonly used when bolting to a concrete floor. It will support the weight of the safe and block moisture from getting under the safe.

https://www.tractorsupply.com/tsc/product/4-ft-x-6-ft-x-3-4-in-thick-rubber-stall-mat

 

[8Ball_99]

You could also just paint the concrete with epoxy under the safe to block any moisture that might come through the cement. My entire room that my safe is in has the concrete sealed with epoxy paint. It's not that expensive now and you can buy it pretty much anywhere.

 

[Blue Jays]

What about pouring concrete into a 6" tall metal square form a bit larger than the footprint of the safe? Then put that on the ground and mount safe to that strong uniform concrete block? Would that provide any moisture advantages, aside from raising the whole safe off the concrete floor itself? Very curious.

 

[CapnMac]

A cut sheet of CDX plywood would suffice, too, as CDX

Would that provide any moisture advantages, aside from raising the whole safe off the concrete floor itself? Very curious.

Not really. Concrete is not water vapor resistant, per se.

Making the pad would create a break between the one batch of concrete and the other.
There's a different issue, though. Let's posit a 30 x 36 x 6 "pad." My calculator renders that as 6480 cubic inches, or 3.75 cubic feet. Concrete is 150pcf, so the pad is only 562.5 pounds. So, an 800# safe might actually be a bit more "tippy" up on the pad--especially with the door open (which creates a significant moment arm).

It's and interesting notion, to be sure. An, having the safe be 6" higher off the floor would make reaching in a bit easier. But, that gets us to the thought exercise where we stand the safe up on 8" concrete block for better access (epoxy and all-thread would get you anchoring).

 

[lightman]

I would put something under it to keep it off of the floor. A scrap piece of plywood, a piece of rubber mat or something.

 

[Rule3]

Why do you feel the need to put something under it? Concrete slabs already have a vapor barrier before the concrete it poured.

Carpet, tile , cabinets, appliances etc are put directly on the concrete slab.

 

[CapnMac]

Concrete slabs already have a vapor barrier before the concrete it poured.

Not always under garages and the like--and historically, only in recent times, and only in placed that have actual Building Inspectors. There's plenty of "mud poured" concrete out there, sadly.

Concrete is not, inherently waterproof. It's extremely water-resistant, but, it's permeable.

Carpet, tile , cabinets, appliances etc are put directly on the concrete slab.

And, if those things rust in contact with a slab, it's less of an issue than when a two-grand RSC does.
And, to make a fine point of it, glue-down carpet is set in a water-proof glue base (it's a bear to take up afterward). Vinyl and similar tile is in a similar mastic base.
"Hard" tiles (ceramic, terra cotta, quarried, etc.) are laid in a mortar base (thin or thick set), then grouted. Those need sealers applied to prevent moisture & water vapor from passing through (unless the slab is sealed first).

 

[Ohen Cepel]

I like a bit of an air gap as I have moved many military safes that were badly rusted on the bottom. I think part of it is from the concrete but maybe also from the cold metal pulling moisture.

Also, keep in mind where your power cord access is on the safe. Don't want to bolt it down and then remember that is it on the bottom flush with the floor now.

If the criminals show up with stuff to rip the bolts out of the floor that bit of gap will not matter. That said, they will likely just show up with a gas powered concrete saw and cut the safe top off if they are that prepared. Which only a major safe upgrade will stop.

 

[hc18flyer]

I made a 4" tall 'riser. The top mates directly to the base of the safe bolts. The bottom has spots for 8 concrete anchors on the inside, inaccessible to thieves. Riser will help in case of a water leak too.

 

[Blue Jays]

"…I made a 4" tall riser. The top mates directly to the base of the safe bolts. The bottom has spots for 8 concrete anchors on the inside, inaccessible to thieves. Riser will help in case of a water leak too…"

Sounds interesting. I am trying to envision your setup.
Water is my main concern, too. A few inches would likely be sufficient for a failed hot water heater or a crazy 100-year rainstorm…even if the two unexpected events occurred simultaneously.

 

[Rule3]

Not always under garages and the like--and historically, only in recent times, and only in placed that have actual Building Inspectors. There's plenty of "mud poured" concrete out there, sadly.

Concrete is not, inherently waterproof. It's extremely water-resistant, but, it's permeable.


And, if those things rust in contact with a slab, it's less of an issue than when a two-grand RSC does.
And, to make a fine point of it, glue-down carpet is set in a water-proof glue base (it's a bear to take up afterward). Vinyl and similar tile is in a similar mastic base.
"Hard" tiles (ceramic, terra cotta, quarried, etc.) are laid in a mortar base (thin or thick set), then grouted. Those need sealers applied to prevent moisture & water vapor from passing through (unless the slab is sealed first).

Well I have lived in Fl my whole life and never seen water coming up through concrete building slabs and used to inspect homes.Regular carpet is not glued down, it is over a pad which would get wet. If water got through the thin set mortar the tile would not stick.
My safe is direct on the concrete slab.
Put a thick piece of plastic under it, then all that water will ooze out around it.
Such a big issue over so little.

 

[danez71]

1st, I just move a cardboard box or anything that's being sitting flat on the concrete and see if it's damp at all.

Next, take a plastic trash bag and tape it flat to the floor all the way around sealing it to the floor.

Wait a week (or 2 if you want), pull it up and see if it looks moist/darker/different.

If it does, you got moisture.

 

[8Ball_99]

Well I have lived in Fl my whole life and never seen water coming up through concrete building slabs and used to inspect homes.Regular carpet is not glued down, it is over a pad which would get wet. If water got through the thin set mortar the tile would not stick.
My safe is direct on the concrete slab.
Put a thick piece of plastic under it, then all that water will ooze out around it.
Such a big issue over so little.

This is actually a real thing. You live in FL so a moisture barrier is probably standard with any slap construction and probably has been for a long time. But concrete can infact wick up moisture. Just read the can on some garage floor paint. They tell you to cover a section of the floor with plastic. Leave it for a day and then check for moisture. If moisture appears do not apply the product. Moisture can also wick in from the side of the slab even with a barrier under the slab. Just like in construction you use treated lumber on a concrete floor because of moisture. With a large flat piece of metal sitting on concrete. It's a smart idea to put down a moisture barrier. Would most have a issue, probably not. But safes are expensive and probably wont be moved for a long time. A rubber mat or some epoxy paint is cheap so why not take the extra precaution?

 

[vintovka]

Many safes come on a 4" steel shipping stand or rails. By adding pressure threated 4x4's you can effectively support the safe while retaining the rails. Blocking the front off keeping migrating parts from making a home underneath and helps from catching shoe toes etc on the sharp edge. Careful thru bolts with anchors in to the concrete and back wall helps. Those who have potential for flooding or even the Hot Water tank issues should avoid direct on concrete installations.

 

[Rule3]

OK, after all the debate, The WINNER is..... A rubber Mat or Epoxy. Direct from Liberty Safe.

https://www.libertysafe.com/blogs/the-vault/your-gun-safe-and-concrete-floors

How to Protect Your Safe
One way to protect your safe from moisture damage is to put a hard rubber mat under it before bolting it down. Another way is to seal the concrete with epoxy before you have your safe installed. Both methods will help protect your safe from moisture damage.

 

[8Ball_99]

OK, after all the debate, The WINNER is..... A rubber Mat or Epoxy. Direct from Liberty Safe.

https://www.libertysafe.com/blogs/the-vault/your-gun-safe-and-concrete-floors

How to Protect Your Safe
One way to protect your safe from moisture damage is to put a hard rubber mat under it before bolting it down. Another way is to seal the concrete with epoxy before you have your safe installed. Both methods will help protect your safe from moisture damage.

Lol that's awesome. Who knew a large safe manufacturer would already have recommendations for a common installation scenario I'm laughing because I've had a few safes over the last 20 years. Never once thought to look what any of the manufacturers suggest when installing.

 

[hso]

Paint the area with garage floor epoxy or use a stall mat.

 

[vintovka]

Mat is good but elevating safe is some insurance against flooding if theres any chance of it happening. . I saw a bunch of rifles and shotguns stocks ruined/damaged when a sump pump failed and they got just enough water to enter the bottom of the safe door. When they replaced the pump they found the guns all sitting in water for weeks and the wood sucked it up.

 

[SunnySlopes]

Re all the above. No danger of electrolysis with safe sitting directly on a concrete floor?

 

[CapnMac]

Re all the above. No danger of electrolysis with safe sitting directly on a concrete floor?

Depends on the slab and who poured it, and under what jurisdiction.

If the local jurisdiction requires a "UFER" ground then there is a potential that the reinforcing grid can be energized to some amount. Floor electrical boxes are not supposed to ground to the rebar, but that's not always "for sure."

Then, the size of the bar and amount of concrete cover matters--3" is better than 2.5" for instance. Mineral content in the aggregate can matter, too.

But, as a general rule, moisture vapor is probably more of a concern than electrolysis--unless the safe winds up energized somehow (keep an eye on electrical cords passing through and ensure they are not chafed).

 

[sonora]

Depends on the slab and who poured it, and under what jurisdiction.

If the local jurisdiction requires a "UFER" ground then there is a potential that the reinforcing grid can be energized to some amount. Floor electrical boxes are not supposed to ground to the rebar, but that's not always "for sure."

Then, the size of the bar and amount of concrete cover matters--3" is better than 2.5" for instance. Mineral content in the aggregate can matter, too.

But, as a general rule, moisture vapor is probably more of a concern than electrolysis--unless the safe winds up energized somehow (keep an eye on electrical cords passing through and ensure they are not chafed).