gun safe, no slab question

Status
Not open for further replies.

HEAVY METAL 1

Member
Joined
Jan 18, 2005
Messages
477
I intend to purchase a gun safe and have the following concerns: I live in an area where most houses are built on a crawl space and do not have basements (Pacific NW) It is damp, rainy in the winter, hot/dry summer . 1) Since there is no concrete slab to bolt a safe to and the safe + guns is very heavy how is the floor braced & safe secured? 2) The temperature & humidity swings over the course of the year concern me as all of my guns have wooden stocks so having the safe in the garage may be an issue.

So, what wise words does the membership have for me?
 
Crawl space makes it extremely simple, though it will take two people. Buy carraige bolts, nuts and washers to fit the safe holes. After drilling the holes through the plywood, you could go about it 2 ways. Simply putting the bolts in from the underside will work, but with enough force the heads will pull through. You can also put a couple of 2x8 (or 6 or 10) blocks underneath, and drill through them. Then insert the bolts from below.

Using the carraige bolts, and inserting them from the bottom up will insure that they cannot be removed except from the inside of the safe.

If you're lucky enough (or good enough) to hit a joist, simply use lag bolts.

Wyman

ETA-As far as bracing goes, if you put it next to a wall that is perpendicular to the joist, there should be a beam under the wall. If not, go to Home Depot and get 2 (we call them elephant feet down here), but they are concrete piers that are designed to have a post sitting on top of them. Run 1 2x across the joists about center of the safe. And put a vertical 4x4 on each end. The "elephant feet" are designed to sit on top of the ground. That'll keep you from having to dig much or having to get wet concrete up under the crawl space. Neither of which is too much fun.
 
Last edited:
If floor strength were a concern to me in that situation ( which is unlikely because a gunsafe wont be a lot heavier per square inch than an upright freezer ) i would build pillars or pilings with cinder block below the safe location to support it . as for securing it you might use some 2" x 1/4 angle iron spaning the safe below the floor joists to bolt to . not real high tech but they are unlikely to be able to snap a couple of floor joists off to tip the safe over .
 
Last edited:
Figure the weight of the safe plus the weight of the guns in it. If it's under a thousand pounds or so, you're probably good to go. If it's more than fifteen hundre pounds, some block pillars on a concrete footer are probably a good idea. Put the carriage bolts up through a healthy slab of 3/16 or 1/4 inch plate under the floor.
 
I would agree with reinforcing it somehow, if the safe weight approaches or exceeds 1,000 lbs with the guns and stuff in it. If you are less than that and it is a relatively wide safe, you are probably fine, as long as you put it near the wall, as the weight will be distributed to 3 or 4 joists and not be much worse than a couple heavy-set guys standing next to each other. The worst thing for a residential floor is usually the focused force on the plywood decking between the joists, not so much the joists themselves, and a safe is big and flat and good at distributing that force. That said, you could theoretically over-load the joists, and it wouldn't be hard at all to reinforce.

The easiest way to reinforce is probably posting up from the ground below as JWF mentions. The other thing you could do, assuming you have the safe near the wall (support) and shear of the joists will be worse than the bending, you could take some 5/8" plywood and screw them into each side of the joists directly under the safe. Just have the plywood go all the way to the wall and continue beyond the safe a few feet.

As for clamping it down, I would vote for some pieces of steel that extend a few feet in each direction and carriage bolt to that. That safe won't be going anywhere!
 
I did the following:

Put down a piece of plywood under the safe and on top of the carpeting. The plywood is a few inches larger than the safe all around.

Place the safe against an exterior wall, which was supported by a continuous brick foundation wall/footing, and which has the floor joists intersecting the wall perpendicularly.

Measured to make sure that the safe was centered over two floor joists, not one.

Crawled under prior to placement and nailed a 4x4 perpendicular across the two referenced joists, directly underneath the front 1/4 of the safe (nearly under the safe door. Then placed a concrete pad, about 1' square or larger on the ground under the center of the 4x4. Then permanently placed a screw jack intended to level mobile homes on the pad and jacked it up against the 4x4, and nailed it to the 4x4.

Bolted the safe down through the wood floor and into some strategically placed 2x4s against the underside of the floor, using lag bolts.

Now it's supported, and you can go adjust the jack anytime you need to.
 
Just how big is this safe? Unless you're looking at something really "bank like" your floors will be fine. As some others said a big freezer filled with stuff is easily heavier than most gun safes unless it will be rather "bank like".

For securing it I'd suggest using a magnet to find the nail or screw heads in the walls where the drywall is held to the studs. Measure out and drill the back of the safe to match the studs and secure with 5/16 or 3/8 lag screws and big washers. For the floor just drill through both safe and floor all at once and secure with 5/16 or 3/8 bolts and washers on the other side or more lag screws is you're lucky enough to hit the joists.

In the winter if your gun safe is in the house you simply do not need to worry about humidity. Heating your house takes care of that as long as your gun safe isn't in the bathroom where you have long steamy showers. It's in the summer when the humidity is higher and you can get fairly severe temperature shifts from day to night. For that the easy way out is to use a small heater in the safe such as the Goldenrod product. It'll keep the insides just enough warmer than the outside that the relative humidity in the safe will always be low during the worst humid times.

Now if you want to store the guns in the garage that's a whole other issue. Again, for the winter you'll want the safe heating with a Goldenrod or similar. You'll also very much want to insulate the safe from the floor or concrete walls with 1.5 to 2 inches of pink or blue styrofoam. Otherwise in the summer the earth contact through the concrete will hold the inside temperature of the safe down and absolutely guarantee condensation and rusty guns. The other factor is just how hot it gets in the garage in the summer. If it's like opening the door to an oven again this isn't a great storage environment for your valuable guns. On the other hand if your garage is insulated and you use it regularly as a shop/man cave then the inside environment may not be any worse than your house.
 
I would determine where you plan in putting the safe in the house. Then crawl underneath and dig out a hole 2 by 2 feet and 12 in deep. This would be difficult and would take some time as it might be tight under the house. Then I'd fill it with cement making sure its nice and level. Once that's has cured you can support the floor with treated wood, but leave enough room so you can secure the safe. I'd probably get some plate steel and send some bolts through the floor and the steel. I've ripped out plenty of crap from houses, and anything bolted to the floor just rock back and forth it will pop right out. The steel would provide a larger service area which would make it much harder to rip out. Also attach to a wall, can use a stud finder. But that should cover it, supported from floor, anchored down to floor and wall.

I like to do things above and beyond, that way you do them once and never have to worry about it again.
 
Heavy Metal 1;

Get a 1/8" steel plate that's larger than the footprint of your safe and will cross at least two floor joists. There are two advantages to doing it this way; 1. bolt-down holes are no longer placement critical. 2. Supporting the plate also has more options. The elephant feet, or foot, are good, given that you can shim, or otherwise fill the space between the top of the foot & the plate. Joist screw jacks are another possibility depending on the clearance you've got in the crawlspace.

Just a caution, if you're going to drill through carpet to do the bolt-down holes, don't. Drills often snag a carpet thread & cause a run. Best is to use a gasket maker's punch & make the carpet hole with that. No snags, then drill through the wooden flooring.

900F
 
If you can conceal the safe all the better. If no one knows you have it and you do have a random break in, the thieves will probably not bring a dolly to move it with. If you allow it to be seen by service people such as plumbers, exterminators or carpet cleaners they may talk. There was an attempted robbery of a safe in my town. It held but was ruined by a cutting torch. So was the carpet and paint as it made a real mess. Someone had to have known about that safe and planned accordingly. The worst part is that the warranty did not apply because the safe held even though it was ruined had to be replaced after a locksmith charged big bucks to get it opened.
 
Fella's;

And the above story contains a caution that all safe owner's need to heed. Always insure the safe itself. The cost is minimal and so is the aftermath anguish.

900F
 
Your floor is designed to hold at least 30 pounds per square foot of dead load, plus another 10 pounds per square foot of 'live' load over the ENTIRE floor all at the same time.

A safe with a 2 ft x 2 ft footprint would load one small area of the floor to the design load if it weighed 160 pounds.
The localized higher spot load is not going to do much of anything, since the rest of the floor likely has almost no load.

Try and put the safe near the end of the joists (outer wall or center beam).
 
Brickeye,

I think you are close but maybe reversed. It is more like 10-30 pounds per square foot dead load, and 30-40 pounds per square foot live load. Of course various state and municipality codes can vary.

In any case, putting the safe near the edge of the joists is smart. A concentrated load of 1,000 lbs at the mid-span of some 20' joists, say 16" on center, and 2 joists share the load, will pretty much equal the 40 pounds per square foot (for bending) and there will be no strength left over for anything else. But even putting the load near the edge is not a guaranteed safe safe (heheh) because the wood can fail in shear. So either talk to an engineer or post up somehow from the foundation. Better safe than sorry.

http://www.huduser.org/Publications/pdf/res2000_2.pdf
 
1) Since there is no concrete slab to bolt a safe to and the safe + guns is very heavy how is the floor braced & safe secured?

At your local building supply store or big box hardware store, they have adjustable columns for just this purpose.

Basically, a piece of pipe, a threaded end and plates on both ends. Place some half concrete blocks on the floor of the crawl space and locate under a floor beam under the safe.

The pipe can be cut if too long and you probably would want at least two of the supports.

Check it periodically to make sure it is still tight, adjust as necessary to keep support under the safe and keep the floor from sagging.

There are numerous methods to control humidity in you gun safe and keep the air dry.
 
Better safe than sorry.

Do not own a gun safe or guns then.

This is called the 'precautionary principal' and will cripple every thing you do in life.

I have heard the best way to avoid dying is to never have been alive.
 
I have the same type of construction. I put my safe in a corner where two bearing wall meet. The floor at this point is sufficiently stout to handle the weight. I then drilled thru the floor and put 2x8's so that they hung below and across the joists and put the bolts thru them. When the bolts were tightened, the 2x8's pulled up agains the joists. This way, I didn't have to drill thru any of the joists, just the flooring and subfloor. On the plus side, it would take an earthquake strong enough to tear down house to knock over the safe.

One suggestion, if you have carpeting, cut it out so that he safe doesn't sit on it. If you don't, and later want to put in new carpet, you either end up cutting around it, or moving the safe.
 
Most of the crawlspaces around here have dirt floors. Are the 'elephant feet ' the concrete square things deck posts are put on? If I put those 'elephant feet' on the dirt, will the weight of supporting the safe sink them into the ground? My concern is that the weight of the safe would be more concentrated in a small spot moreso than a deck. The home construction here is so crappy that I can feel the floor give when my wife walks by my recliner-and NO she's not a whale, she is thin, she's a dietician. My recliner is < 3 ft from a load bearing wall. Why the heck they don't pour basements around here I do not know.
 
Better safe than sorry.

Do not own a gun safe or guns then.

This is called the 'precautionary principal' and will cripple every thing you do in life.

I have heard the best way to avoid dying is to never have been alive.

Hmmm. Whatever you say man. I'll go tell all my engineering colleagues and friends.

Most of the crawlspaces around here have dirt floors. Are the 'elephant feet ' the concrete square things deck posts are put on? If I put those 'elephant feet' on the dirt, will the weight of supporting the safe sink them into the ground? My concern is that the weight of the safe would be more concentrated in a small spot moreso than a deck. The home construction here is so crappy that I can feel the floor give when my wife walks by my recliner-and NO she's not a whale, she is thin, she's a dietician. My recliner is < 3 ft from a load bearing wall. Why the heck they don't pour basements around here I do not know.

I wouldn't worry too much about the elephant feet sinking in. Even pretty crummy native soil is good for 1,500 pounds per square foot. If it is native soil it might be a little softer, if it is engineered fill then it will be a harder. You'll have to make a judgment on that. Worst case scenario, for peace of mind, put some plywood boards underneath to help distribute the force over a wider area. That is, if it doesn't cripple you :rolleyes:
 
Most of the crawlspaces around here have dirt floors. Are the 'elephant feet ' the concrete square things deck posts are put on? If I put those 'elephant feet' on the dirt, will the weight of supporting the safe sink them into the ground?

The answer is "it depends." It depends on how big the footings are, how deep they are buried in the soil, the engineering characteristics of the soil including its degree of compaction and moisture content, and of course the total load placed on the footing. Foundation design is a subject unto itself. Rather than hire an engineer to calculate the answer, you may wish to simply overcompensate by using, oh let's say four, of the little post footings or one big house footing.
 
Status
Not open for further replies.
Back
Top