Bolting Down Safe

[diginit]

Even with redheads or other lead anchors into a concrete slab at the bottom of the safe. There is enough leverage at the top to pull them out. Mount to the floor and the to the wall. The more lag bolts into the wall studs the better. The weight of the safe makes no difference. Picture a lever and fulcrum. The top of the safe is the lever and the bottom corner is the fulcrum. Easy to dislodge the bottom bolts closest to the wall and the weight of the safe will pull out the 2 on the front while falling. Two guys carry it away. Much harder to dislodge the wall mounts. I have installed alot of safes in private residences professionally. If you can hit a stud at opposing angles on the wall mounts. It's much stronger. 4 bolts to the floor. 2 to the top rear, And 2 to one or both sides near the top. Mid section bolts just increase strength. If only corner mounting is available. Opposing angles At 12" center. One towards the right and one towards the left.. And so on... The Xmas tree effect.

[UserM4]

I dunno but wedge anchor bolts are seriously tough stuff. Four of them will require a truck to pull the safe out of the ground. Unless the bad guys plan on backing a diesel truck up to your garage and wrapping a huge chain around your safe, I think you'll be just fine.

[kermitz]

It will be a newer home usually. and i have seen it labeled as such in the garage and on the floor.

My current home has a stamp in the garage floor that says "post tension slab, do not drill or core". It was bulit in 2010. I have yet to bolt my safe down.

[reggie 00]

I havnt noticed any labeling, house was build in 1970??

Your good to go. Drill away, And like the previous poster add some wall lags. Whwn i did mine i used an anchor from HD that was basically a thread-sert and bolt. Worked outstanding. for added umph i hit two wall studs with lags. Dont forget to check your level before you bolt it all in place. My floor slopes and it made the door swing on its own. I shimmed the front before i bolted it down solid.

Yea Im going to have to find out about the concrete in the garage. The house was remodeled a couple years ago. So it should say on the garage floor somewhere?

They would have labled your floor if they changed it. For a remodel i cant see them busting up the garage and post tentioning it. Lots of work, lots of money compared to simple slab.

My current home has a stamp in the garage floor that says "post tension slab, do not drill or core". It was bulit in 2010. I have yet to bolt my safe down.

You sir need to contact your builder and ask for the drawings. I want to say they have a drawing that shows whats what on that floor. My brother bought a house just recently and the builder is pretty helpful in situations like this, so hopefully your's will too.

[jak77]

I dunno but wedge anchor bolts are seriously tough stuff. Four of them will require a truck to pull the safe out of the ground. Unless the bad guys plan on backing a diesel truck up to your garage and wrapping a huge chain around your safe, I think you'll be just fine.

Yea I think these should be enough. Unless my garage is post tensioned. Can anyone explain to me in brief what post tensioning is and why you aren't supposed to drill into it?

[paul0660]

post tensioning means tensioning AFTER the concrete is poured. There are cables in the slab that can be tightened to increase the shear strength of the concrete, as opposed to conventional pouring with inert mesh or rebar. Drilling post tensioned concrete messes with the integrity of the entire slab. Actually a few small holes probably won't matter, but it could be cataclysmic as well.

I don't recall hearing about post tensioned garage slabs before 2000 or even later. The technique actually has been around since the 40's.

[jak77]

post tensioning means tensioning AFTER the concrete is poured. There are cables in the slab that can be tightened to increase the shear strength of the concrete, as opposed to conventional pouring with inert mesh or rebar. Drilling post tensioned concrete messes with the integrity of the entire slab. Actually a few small holes probably won't matter, but it could be cataclysmic as well.

I don't recall hearing about post tensioned garage slabs before 2000 or even later. The technique actually has been around since the 40's.

Thank you, Ill check to see if mine is or isnt today. Hope it isnt.

[paul0660]

Should be a label or plaque inset into the concrete as you go into the roll up door.

[IntoForever]

Problem with post tension slabs is when you damage a cable. I forgot what the tension is but one of the iron workers I used to work with said they were setting a cable and when it popped, it cut the slab in two pieces and destroyed everything above it, including walls. You don't even want to nick one of those cables.

[SJgunguy24]

You can drill into post tension, I've drilled thousands of holes into post tension concrete slabs. The cables are blocked up and set in the center of the slab if it's done right. You can drill 1" in the slab top or bottom, use a Hilti drop in anchor and make sure the square imprint from the set tool is clear when set. The 3/8" are good for over 2000lbs, I've hung 800lb+ exhaust fans using drop in anchors in post tension concrete slabs.

[Dreaded Claymore]

What are post tensioned slabs good for, in the context of a garage floor? I mean, I know they have more tensile strength, but is that any kind of advantage for this application over ordinary rebar concrete?

Or is it just the same principle as spending extra money for a free-floated barrel on your rifle even though you shoot much worse than the rifle does? (I am one of those who does such things.)

[SJgunguy24]

What are post tensioned slabs good for, in the context of a garage floor? I mean, I know they have more tensile strength, but is that any kind of advantage for this application over ordinary rebar concrete?

Or is it just the same principle as spending extra money for a free-floated barrel on your rifle even though you shoot much worse than the rifle does? (I am one of those who does such things.)

From what I have noticed is post tension slabs tend to be thinner, and lighter. Saves money on the mix and rebar since less is used for post tension slabs. Also I have never seen any post tension for commercial construction, only residential and this includes high rise apartment buildings. All commercial buildings I see have corrugated pan deck with rebar laid on iron beams or truss systems.

[Dave A]

Not an engineer, but from what I have seen and read, post tensioned slabs are used where the soils are difficult and subject to a lot of expansion and contraction from wet to dry. If you build a house on expansive soils (much of So Calif) you can get a lot of differential movement, which causes cracks and settlement. The end result is very unhappy homeowners.

Post tensioning is also used in overpasses, where there is a long span between piers.

[retired]

I was going to put mine in the garage and bolt it in when I bought it brand new in 2006. Thankfully I mentioned to the superintendent, who I had become friendly with not to do it because of the post tension slab.

It has been mentioned a couple of times in this thread, but for those who don't know, it means that in the middle of the slab, there are steel cables that criss cross the width and length of the slab. If you drill into the slab and hit the steel it may result in serious injury or death.

The super told me of some stories that occurred in the construction industry where workers had been very seriously injured and some decapitated when the steel whips out and strikes the worker. They had some pics in their trailer that showed some of the lesser serious injuries.

Mine was put into a closet as a result and not bolted into the slab.

[SJgunguy24]

I was going to put mine in the garage and bolt it in when I bought it brand new in 2006. Thankfully I mentioned to the superintendent, who I had become friendly with not to do it because of the post tension slab.

It has been mentioned a couple of times in this thread, but for those who don't know, it means that in the middle of the slab, there are steel cables that criss cross the width and length of the slab. If you drill into the slab and hit the steel it may result in serious injury or death.

The super told me of some stories that occurred in the construction industry where workers had been very seriously injured and some decapitated when the steel whips out and strikes the worker. They had some pics in their trailer that showed some of the lesser serious injuries.

Mine was put into a closet as a result and not bolted into the slab.

They don't whip, they pop and cause a ripple in the slab and shoot out the side. If they whip, the rebar boss is in a lot of trouble, the cables are supposed to be centered in the slab with rebar above and below the cable. We're allowed to drill 1" into the slab and the anchors cannot be closer then 6" from the edge of a slab. If so then we need to place inserts befroe the slab is poured or have steel inserts that we weld our hangers to. Also, if we drill, the anchors cannot be closer the 6times the diameter of the hole drilled edge to edge. 3/8" Wedge anchors=3/8 hole, no closer then 2.5" apart E2E.
3/8" drop in=1/2" hole, no closer then 3" E2E.
I've drilled into cables, I've been there when cables have popped.